Uridine diphosphate derivatives, prodrugs, compositions and uses thereof

ABSTRACT

This disclosure relates to the use of uridine diphosphate (UDP) derivatives, salts and/or prodrugs thereof for the treatment of inflammatory conditions (e.g., psoriasis) and glaucoma, to prodrugs of UDP derivatives, compositions comprising therapeutically effective amounts of those prodrugs of the UDP derivatives and methods of using those prodrugs for treating various disorders including, e.g., neuronal disorders, including neurodegenerative disorders (e.g., Alzheimer&#39;s disease, Parkinson&#39;s disease) and traumatic CNS injury, pain, Down Syndrome (DS), glaucoma, and inflammatory conditions, e.g., psoriasis and rheumatoid arthritis.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.14/432,104, filed on Mar. 27, 2015, which is a national stageapplication under 35 U.S.C. § 371 of International Patent ApplicationNo. PCT/US2013/062413, filed on Sep. 27, 2013, which claims the benefitof and priority from U.S. Provisional Patent Application Nos.61/707,568, filed Sep. 28, 2012, and 61/780,171, filed Mar. 13, 2013.Each of the foregoing applications is incorporated herein by referencein its entirety.

FIELD OF THE INVENTION

This disclosure relates to compounds, their salts and prodrugs,compositions and methods for treating neuronal disorders, includingneurodegenerative disorders (e.g., Alzheimer's disease, Parkinson'sdisease) and traumatic CNS injury, pain, Down Syndrome (DS), glaucomaand inflammatory conditions.

BACKGROUND OF THE INVENTION

P₂Y receptors are G-protein-coupled receptors (GPCRs) that areselectively activated by naturally occurring extracellular nucleotides,including, for example, adenine and pyrimidine nucleotides. There aretwo clusters of P₂Y receptors: the G_(q)-coupled P₂Y₁-like receptors,including P₂Y_(1,2,4,6,11) subtypes; and the G_(i)-coupled P₂Y₁₂-likereceptors, including P₂Y_(12,13,14) subtypes. Of the four P₂Y receptors,i.e., P₂Y_(2,4,6,14) subtypes, which can be activated by pyrimidinenucleotides, the P₂Y₂ and P₂Y₄ subtypes are activated by uridinetriphosphate (UTP), P₂Y₆ receptor is activated by uridine diphosphate(UDP), and P₂Y₁₄ is activated by UDP or UDP-glucose.

The P₂Y₆ receptor has been implicated in a number of disorders,including, for example, neurodegeneration, osteoporosis, ischemic effectin skeletal muscle, and diabetes. It has been reported that agonists ofP₂Y₆ receptor counteract apoptosis induced by tumor necrosis factor α inastrocytoma cells and induce protection in a model of ischemic hindlegskeletal muscle. P₂Y₆ receptor was also reported to play a role inphagocytosis in microglial cells when activated by its endogenousagonist UDP. See, e.g., Malmsjo et al. BMC Pharmacol. 2003, 3, 4;Balasubramanian et al. Biochem. Pharmacol. 2010, 79, 1317-1332; Kim etal. Cell. Mol. Neurobiol. 2003, 23, 401-418; Mamedova et al. Pharmacol.Res. 2008, 58, 232-239; Korcok et al. J. Biol. Chem. 2005, 58, 232-239;and Koizumi et al. Nature, 2007, 446, 1091-1095. These reports suggestthat ligands of the P₂Y₆ receptor are of interest in the search for newtreatments for P₂Y₆ receptor-related conditions.

Therefore, there is a need for new ligands, such as agonists, of P₂Y₆receptor activity that are useful in therapeutic preparations for thetreatment of disorders mediated by the receptor, includingneurodegeneration, traumatic brain injury and pain.

SUMMARY OF THE INVENTION

The present disclosure addresses the aforementioned need by providingcompounds of formulae I and II:

wherein the variables are as defined herein, along with the prodrugs andthe pharmaceutically acceptable salts thereof. In certain embodiments,these compounds, salts and prodrugs are selective ligands of the P₂Y₆receptor. In certain other embodiments, the compounds, salts andprodrugs as described herein can modulate, for example, agonize, P₂Y₆receptor activity, for example, where the compounds, salts and prodrugsas described herein are agonists of the P₂Y₆ receptor. Compounds offormulae I (including, I-A) and II and their salts and prodrugs can beused to treat the conditions as described herein.

The present disclosure also provides compositions that comprise theabove compounds, or a prodrug or a pharmaceutically acceptable saltthereof. The disclosure also includes the use of the compounds, salts orprodrugs disclosed herein in the manufacture of a medicament for thetreatment of one or more of the conditions described herein.

In another aspect of the disclosure, there is provided methods forstudying P₂Y₆ receptor activity using the agonists of the disclosure,which include the compounds of all formulae disclosed herein, all of theindividual compounds disclosed herein, and all of their prodrugs andsalts. For example, cells in culture may be contacted with one or moreof the compounds, salts, and prodrugs provided herein and their impacton P₂Y₆ receptor activity, as well as cellular function, can beevaluated. Such studies are useful for evaluating the use of agonists ofthe disclosure as in vitro research tools for evaluating P₂Y₆ receptoractivity and its cellular and biochemical impact on different celltypes.

In another aspect of the disclosure, there is provided a method ofmodulating P₂Y₆ receptor activity by using one or more of the compounds,prodrugs or salts described herein. For example, the invention providesa method of modulating P₂Y₆ receptor activity in a patient in needthereof by administering to the patient a therapeutically effectiveamount of one or more of the compounds, prodrugs, or salts describedherein. Similarly, the invention provides a method of modulating P₂Y₆receptor activity in a patient in need thereof by administering to thepatient a therapeutically effective amount of one or more of thecompounds, prodrugs or salts described herein in a pharmaceuticalcomposition.

In another aspect of the disclosure, there is provided a method fortreating neuronal disorders, including neurodegenerative disorders(e.g., Alzheimer's disease, Parkinson's disease) and traumatic CNSinjury, pain, Down Syndrome (DS), and glaucoma in a subject in need orat risk thereof using a compound, salt or prodrug described herein.

In another aspect, the disclosure provides methods for decreasing plaqueburden, improving cognitive function, decreasing or delaying cognitiveimpairment, improving or restoring memory, enhancing synapticplasticity, or improving hippocampal long term potentiation byadministering to a subject in need or at risk thereof a P₂Y₆ receptoragonist. Also provided are methods of enhancing beta amyloid clearance.Subjects in need include subjects having Alzheimer's disease (includingsubjects suspected of having Alzheimer's disease). Additional subjectsin need thereof are subjects having Down Syndrome, and administration ofa P₂Y₆ receptor agonist is used to treat Down Syndrome by, for example,improving cognitive function, decreasing cognitive impairment, improvingor restoring memory, improving hippocampal long term potentiation,enhancing synaptic plasticity, or enhancing clearance of beta amyloid.Further subjects in need thereof are subjects having Parkinson'sdisease. Exemplary P₂Y₆ receptor agonists are disclosed herein.

In another aspect, the disclosure provides methods for clearing orotherwise decreasing extracellular alpha-synuclein, decreasingintracellular accumulation of alpha-synuclein, and/or decreasing orpreventing the formation of Lewy bodies in a subject in need thereof byadministrating a P₂Y₆ receptor agonist to the subject. In certainembodiments, the subject in need thereof is a subject having Parkinson'sdisease, and administration of a P₂Y₆ receptor agonist of the disclosureprovides a method of treating Parkinson's disease by, for example,improving or preventing further motor impairment associated withParkinson's disease and/or improving or preventing memory impairment andother symptoms of neurodegeneration. Without being bound by theory,phagocytosis of extracellular alpha-synuclein, which may be promoted bythe P₂Y₆ receptor agonists, decreases extracellular and intracellularaccumulation of alpha-synuclein, as well as Lewy body formation and theresulting neurodegeneration.

In another aspect, the disclosure provides methods for treating glaucomaby administering to a subject in need thereof an effective amount of oneor more of the compounds, salts or prodrugs disclosed herein. In certainembodiments, administration of an effective amount of one or more of thecompounds, salts or prodrugs can decrease intraocular pressure in thesubject in need thereof.

In another aspect, the disclosure provides methods for treating aninflammatory condition in a subject in need thereof comprisingadministering to the subject an effective amount of one or more of thecompounds, salts or prodrugs according to the present disclosure. Incertain embodiments, the disclosure provides a method for reducing theplasma concentration of one or more cytokines of a subject, such as asubject with an inflammatory condition. Suitable cytokines are describedherein. In either case, the disclosure provides numerous examples ofinflammatory conditions which may be treated (e.g., the subject in needthereof has an inflammatory condition described herein). In certainembodiments, the subject is administered an effective amount of acompound, salt or prodrug of the disclosure. In certain embodiments, theinflammatory condition is not Alzheimer's disease and/or the subjectbeing treated does not have, and/or has not been diagnosed with, and/oris not suspected of having Alzheimer's disease.

In certain embodiments, the disclosure provides a method of treating aninflammatory condition characterized, in whole or in part, by elevatedIL-12 and/or increased IL-12 activity by administering a compound, saltor prodrug of the disclosure. Exemplary conditions are described herein.Similarly the disclosure provides a method of treating an inflammatorycondition characterized, in whole or in part, by elevated levels of oneor more of IL-4, IL-10, or IL-12. Methods of reducing the plasmaconcentration of one or more of any of these cytokines are alsoprovided.

In certain embodiments, the disclosure provides methods for treating oneor more of: rheumatoid arthritis, psoriasis, psoriatic arthritis,atherosclerosis, Crohn's disease, ulcerative colitis, irritable bowelsyndrome, or multiple sclerosis.

In certain embodiments, the disclosure provides methods for treating anyof the conditions described herein, such as in a subject at risk fordeveloping the condition, by initiating treatment prior to onset of oneor more symptoms and/or prior to achieving a level of decline at whichstandard of care treatment is typically initiated. In such prophylacticembodiments, the disclosure contemplates, in certain embodiments, thattreatment delays onset of symptoms and/or delays further decline and/orreduces severity of symptoms.

The disclosure contemplates combinations of any of the aspects and/orembodiments described herein. For example, any of the compoundsdescribed herein, such as any of the P₂Y₆ modulating compounds (e.g.,compounds that modulate P₂Y₆ receptor activity) described herein, may beused in the treatment of any of the conditions described herein, such asby administering an effective amount to a subject in need thereof.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 shows two-photon microscopy images of the amyloid plaques labeledwith methoxyX04 in the barrel cortex in living PSAPP mice: (A) image onday 1; (B) magnified view of the portion of the image in the white boxin FIG. 1A, in which the blood plasma was labeled with Rhodaminedextran; (C) magnified view of the portion of the image in the white boxin FIG. 1A, where the arrows indicate dense core plaques; (D) image ofthe same imaging area on day 4, after the injection of UDP; (E)magnified view of the portion of the image in the white box in FIG. 1D,in which the blood plasma was labeled with Rhodamine dextran; and (F)magnified view of the portion of the image in the white box in FIG. 1D,where the arrows indicate dense core plaques.

FIG. 2 shows a quantitative analysis of the number of plaques, plaqueload and size of cross-section of individual plaques in the barrelcortex in PSAPP mice after treatment with UDP or artificial cerebralspinal fluid (ACSF): (A) quantitative analysis of the number of plaques;(B) quantitative analysis of the plaque load; (C) quantitative analysisof the size of cross-section of plaques; (D) UDP treatment reducesplaque load as shown by significant reductions in day 4/day 1 ratios ofplaque load; and (E) UDP treatment reduces number of plaques as shown bysignificant reductions in day 4/day 1 ratios of plaque load.

FIG. 3 shows postmortem immunohistochemistry analysis of the plaque loadin cortex and hippocampus of PSAPP mice after treatment with UDP.Amyloid beta peptide specific antibodies β1-40 and β 1-42 were used inthe immunohistochemistry analysis: (A) immunohistochemistry analysisusing β1-40 on day 1; (B) immunohistochemistry analysis using β1-40 onday 4, after treatment with UDP; (C) immunohistochemistry analysis usingβ1-42 on day 1; and (D) immunohistochemistry analysis using β1-42 on day4, after treatment with UDP.

FIG. 4 shows quantification of plaque load (%) in the cortex andhippocampus of the PSAPP mice after treatment with UDP or ACSF. Amyloidbeta peptide specific antibodies β1-40 and β1-42 were used in thequantification. (A) plaque load (%) in cortex using β1-40 staining; (B)plaque load (%) in hippocampus using β1-40 staining; (C) plaque load (%)in cortex using β1-42 staining; (D) plaque load (%) in hippocampus usingβ1-42 staining; (E) UDP treatment decreased soluble Aβ40 level detectedwith ELISA; and (F) UDP treatment decreased soluble Aβ42 level detectedwith ELISA.

FIG. 5 shows a postmortem immunohistochemistry analysis of the plaqueload in cortex and hippocampus of PSAPP mice after intraperitoneal(i.p.) injection of 3-phenacyl-UDP for 2, 4 and 6 consecutive days.Amyloid beta specific antibody β1-40 was used in the analysis. (A)immunohistochemistry analysis using β1-40 without 3-phenacyl-UDPtreatment; (B) immunohistochemistry analysis using β1-40 afterintraperitoneal injection of 3-phenacyl-UDP for 2 consecutive days; (C)immunohistochemistry analysis using β1-40 after intraperitonealinjection of 3-phenacyl-UDP for 4 consecutive days; and (D)immunohistochemistry analysis using β1-40 after intraperitonealinjection of 3-phenacyl-UDP for 6 consecutive days.

FIG. 6 shows quantification of plaque load (%) in cortex (Cx) andhippocampus (Hp) of the PSAPP mice after treatment with 3-phenacyl-UDPor vehicle control for 2, 4, 6 consecutive days and for 6 days+2 weeks.The vehicle controls used for intracerebroventricular (icv) andIntraperitoneal (ip) administration of compounds were ACSF and saline,respectively. Amyloid beta peptide specific antibody β1-40 was used inquantification. (A) Plaque load (%) in cortex using β1-40 staining; (B)plaque load (%) in hippocampus using β1-40 staining; (C) Aβ40 plaqueload (%) in hippocampus after one week of daily treatment with3-phenacyl-UDP (PSB0474) at three doses; (D) Aβ42 plaque load (%) inhippocampus after one week of daily treatment with 3-phenacyl-UDP(PSB0474) at three doses; (E) Aβ40 plaque load (%) in cortex after oneweek of daily treatment with 3-phenacyl-UDP (PSB0474) at three doses;and (F) Aβ42 plaque load (%) in cortex after one week of daily treatmentwith 3-phenacyl-UDP (PSB0474) at three doses.

FIG. 7 shows freezing behavior (freezing %) of PASPP mice in fearconditioning studies after treatment with ACSF or UDP: (A) freezingbehavior (freezing %) of PASPP mice 5 minutes following treatment withACSF and UDP; (B) analysis of total freezing percentage of PSAPP micetreated with ACSF or UDP; and (C) using the contextual fear conditioningtest PSAPP mice treated with ACSF (white bar) showed significantly lessfreezing time compared to the age-matched wildtype (line bar),suggesting the memory deficits in PS1/APP; UDP-treatment 3 days prior tothe test significantly improved the freezing behavior (black bar)compared to ACSF treatment.

FIG. 8 shows hippocampal long-term potentiation (LTP) recorded as fieldexcitatory postsynaptic potential (fEPSP) % in PSAPP mice, withhigh-frequency stimulation (HFS), 100 pulses at 100 Hz, four times in20-second intervals: (A) depressed LTP (fEPSP %) at the schaffercollateral synapse within the CA1 area of the hippocampus in aged PSAPPmice (PSAPP+/+), as compared to littermates (PSAPP−/−); (B) increasedLTP (fEPSP %) in PSAPP mice after treatment with UDP or ACSF; (C)analysis of the last 15 min potentiation, as fEPSP slope (%), in PSAPPmice.

FIG. 9 shows freezing behavior (as freezing %) of PASPP mice in fearconditioning studies after treatment with 3-phenacyl-UDP (PSB0474). (A)freezing behavior (freezing %) of control littermates (PSAPP−/−), andPASPP mice 5 minutes following treatment with saline vehicle control orwith 3-phenacyl-UDP (PSB0474) at two different dosages, i.e. 1 μg/ml and1 mg/ml; (B) analysis of total freezing percentage of PSAPP mice; and(C) using the contextual fear conditioning test PSAPP mice treated withACSF (white bar) showed significantly less freezing time compared to theage-matched wildtype (line bar), demonstrating the memory deficits inPS1/APP; one week treatment with 1 μg/kg 3-phenacyl-UDP (PSB0474) (greybar) rescued the memory deficit as compared to the vehicle treatment(white bar).

FIG. 10 shows dose-response activation of the P₂Y₆ receptor usingcompounds of the present disclosure, where compounds were tested foractivation of P₂Y₆ receptor by measuring receptor induced Ca²⁺ changeswith the fluorescent Ca²⁺ indicator fluo-4: (A) dose-response activationof the P₂Y₆ receptor using the sodium salt of compound 6; (B)dose-response activation of the P₂Y₆ receptor using the sodium salt ofcompound 3; (C) dose-response activation of the P₂Y₆ receptor using thesodium salt of compound 4; (D) dose-response activation of the P₂Y₆receptor using the sodium salt of compound 1; (E) dose-responseactivation of the P₂Y₆ receptor using the sodium salt of compound 5; (F)dose-response activation of the P₂Y₆ receptor using the sodium salt ofcompound 44; (G) dose-response activation of the P₂Y₆ receptor using thesodium salt of compound 45; (H) dose-response activation of the P₂Y₆receptor using the sodium salt of compound 46; (I) dose-responseactivation of the P₂Y₆ receptor using the sodium salt of compound 47;(J) dose-response activation of the P₂Y₆ receptor using the sodium saltof compound 48; and (K) dose-response activation of the P₂Y₆ receptorusing the sodium salt of compound 49.

FIG. 11 shows freezing behavior (freezing %) of PASPP mice in fearconditioning studies after treatment with vehicle control or compound 5:using the contextual fear conditioning test PSAPP mice treated withvehicle control (black bar) showed significantly less freezing timecompared to the age-matched wildtype (white bar), suggesting the memorydeficits in PSAPP; administration of compound 5 prior to the testsignificantly improved the freezing behavior (line bar) compared to thecontrol treatment indicating that compound 5 restores memory.

FIG. 12 shows plaque load in cortex (Cx) and hippocampus (Hp) of thePSAPP mice after treatment with compound 5 or vehicle control. (A) Aβplaque load (%) in cortex after treatment with compound 5 or vehiclecontrol; (B) Aβ plaque load (%) in hippocampus after treatment withcompound 5 or vehicle control; and (C) postmortem immunohistochemistryanalysis of the Aβ42 plaque load in cortex and hippocampus of PSAPP miceafter treatment with compound 5 or vehicle control. Amyloid betaspecific antibody β1-42 was used in the analysis.

FIG. 13 summarizes plasma cytokine levels (pg/ml) in wildtype and PSAPPmice treated for 7 days (i.p.) with vehicle or compound 5 (1 μg/kg).Plasma cytokine levels are measured in pg/ml. The x-axis of the graphshows the various cytokines examined and the y-axis representsconcentration. For each cytokine shown along the x-axis, the graphprovides four bars indicative of the results for the various treatmentgroups which are, from left to right: untreated wildtype animals,wildtype animals treated with compound 5, untreated PSAPP animals, andPSAPP animals treated with compound 5.

FIG. 14 summarizes results of a fear conditioning assay. PSAPP mice weretreated daily for 100 days with vehicle or the nucleoside of compound 5(10 μg/kg). Compound or vehicle was administered intraperitoneally(i.p.). The mice were then assessed in a fear conditioning task formemory formation.

FIG. 15 summarizes results illustrating decrease in plaque burdenfollowing 100 days of treatment with the nucleoside of compound 5.

FIG. 16 summarizes plasma cytokine levels (pg/ml) in PSAPP mice treateddaily for 100 days with vehicle or the nucleoside of compound 5 (10μg/kg). Compound or vehicle was administered intraperitoneally (i.p.).Concentration of plasma cytokine levels are measured in pg/ml, asrepresented on the y-axis. For each cytokine examined, plasma levels ofvehicle treated or compound treated animals are shown, as represented onthe x-axis. Data for the following cytokines are presented: IL-4, IL-9,IL-5, IL-10, IL-6, IL-12, and IL-7. For IL-12, levels of just the p40subunit (p40), as well as levels of the heterodimeric cytokine (p70) areassayed.

FIG. 17 summarizes plasma cytokine levels (pg/ml) in PSAPP mice treatedfor 100 days with vehicle or the nucleoside of compound 5 (10 μg/kg).Compound or vehicle was administered intraperitoneally (i.p.).Concentration of plasma cytokine levels are measured in pg/ml, asrepresented on the y-axis. For each cytokine examined, plasma levels ofvehicle treated or compound treated animals are shown, as represented onthe x-axis. Data for the following cytokines are presented: eotaxin,IL-1α, G-CSF, IL-1β, GM-CSF, IL-2, IFN-r, IL-3.

FIG. 18 summarizes plasma cytokine levels (pg/ml) in PSAPP mice treatedfor 100 days with vehicle or the nucleoside of compound 5 (10 μg/kg).Compound or vehicle was administered intraperitoneally (i.p.).Concentration of plasma cytokine levels are measured in pg/ml, asrepresented on the y-axis. For each cytokine examined, plasma levels ofvehicle treated or compound treated animals are shown, as represented onthe x-axis. Data for the following cytokines are presented: IL-13, KC,IL-15, LIF, IL-17, LIX, IP-10, and MCP-1.

FIG. 19 summarizes plasma cytokine levels (pg/ml) in PSAPP mice treatedfor 100 days with vehicle or the nucleoside of compound 5 (10 μg/kg).Compound or vehicle was administered intraperitoneally (i.p.).Concentration of plasma cytokine levels are measured in pg/ml, asrepresented on the y-axis. For each cytokine examined, plasma levels ofvehicle treated or compound treated animals are shown, as represented onthe x-axis. Data for the following cytokines are presented: M-CSF, MIP2,MIG, RANTES, MIP-1a, and MIP-1b, and TNFα.

DETAILED DESCRIPTION OF THE INVENTION A. Definitions

Unless otherwise defined herein, scientific and technical terms used inthis application shall have the meanings that are commonly understood bythose of ordinary skill in the art. Generally, nomenclature used inconnection with, and techniques of, chemistry, cell and tissue culture,molecular biology, cell and cancer biology, neurobiology,neurochemistry, virology, immunology, microbiology, pharmacology,genetics and protein and nucleic acid chemistry, described herein, arethose well known and commonly used in the art.

The methods and techniques of the present disclosure are generallyperformed, unless otherwise indicated, according to conventional methodswell known in the art and as described in various general and morespecific references that are cited and discussed throughout thisspecification. See, e.g. “Principles of Neural Science”, McGraw-HillMedical, New York, N.Y. (2000); Motulsky, “Intuitive Biostatistics”,Oxford University Press, Inc. (1995); Lodish et al., “Molecular CellBiology, 4th ed.”, W. H. Freeman & Co., New York (2000); Griffiths etal., “Introduction to Genetic Analysis, 7th ed.”, W. H. Freeman & Co.,N.Y. (1999); and Gilbert et al., “Developmental Biology, 6th ed.”,Sinauer Associates, Inc., Sunderland, Mass. (2000).

Chemistry terms used herein are used according to conventional usage inthe art, as exemplified by “The McGraw-Hill Dictionary of ChemicalTerms”, Parker S., Ed., McGraw-Hill, San Francisco, Calif. (1985).

All of the above, and any other publications, patents and publishedpatent applications referred to in this application are specificallyincorporated by reference herein. In case of conflict, the presentspecification, including its specific definitions, will control.

The term “agent” is used herein to denote a chemical compound (such asan organic or inorganic compound, a mixture of chemical compounds), abiological macromolecule (such as a nucleic acid, an antibody, includingparts thereof as well as humanized, chimeric and human antibodies andmonoclonal antibodies, a protein or portion thereof, e.g., a peptide, alipid, a carbohydrate), or an extract made from biological materialssuch as bacteria, plants, fungi, or animal (particularly mammalian)cells or tissues. Agents include, for example, agents that are knownwith respect to structure, and those that are not known with respect tostructure. The P₂Y₆ receptor binding activity (such as agonist activity)of such agents may render them suitable as “therapeutic agents” in themethods and compositions of this disclosure.

A “patient,” “subject,” or “individual” are used interchangeably andrefer to either a human or a non-human animal. These terms includemammals, such as humans, primates, livestock animals (including bovines,porcines, etc.), companion animals (e.g., canines, felines, etc.) androdents (e.g., mice and rats).

“Treating” a condition or patient refers to taking steps to obtainbeneficial or desired results, including clinical results. Beneficial ordesired clinical results include, but are not limited to, alleviation,amelioration, or slowing the progression, of one or more symptomsassociated with a neuronal disorder, including neurodegeneration andtraumatic brain injury, as well as pain. In certain embodiments,treatment may be prophylactic. Exemplary beneficial clinical results aredescribed herein.

“Administering” or “administration of” a substance, a compound or anagent to a subject can be carried out using one of a variety of methodsknown to those skilled in the art. For example, a compound or an agentcan be administered, intravenously, arterially, intradermally,intramuscularly, intraperitoneally, subcutaneously, ocularly,sublingually, orally (by ingestion), intranasally (by inhalation),intraspinally, intracerebrally, and transdermally (by absorption, e.g.,through a skin duct). A compound or agent can also appropriately beintroduced by rechargeable or biodegradable polymeric devices or otherdevices, e.g., patches and pumps, or formulations, which provide for theextended, slow or controlled release of the compound or agent.Administering can also be performed, for example, once, a plurality oftimes, and/or over one or more extended periods. In some aspects, theadministration includes both direct administration, includingself-administration, and indirect administration, including the act ofprescribing a drug. For example, as used herein, a physician whoinstructs a patient to self-administer a drug, or to have the drugadministered by another and/or who provides a patient with aprescription for a drug is administering the drug to the patient.

Appropriate methods of administering a substance, a compound or an agentto a subject will also depend, for example, on the age of the subject,whether the subject is active or inactive at the time of administering,whether the subject is cognitively impaired at the time ofadministering, the extent of the impairment, and the chemical andbiological properties of the compound or agent (e.g. solubility,digestibility, bioavailability, stability and toxicity). In someembodiments, a compound or an agent is administered orally, e.g., to asubject by ingestion. In some embodiments, the orally administeredcompound or agent is in an extended release or slow release formulation,or administered using a device for such slow or extended release.

A “therapeutically effective amount” or a “therapeutically effectivedose” of a drug or agent is an amount of a drug or an agent that, whenadministered to a subject will have the intended therapeutic effect. Thefull therapeutic effect does not necessarily occur by administration ofone dose, and may occur only after administration of a series of doses.Thus, a therapeutically effective amount may be administered in one ormore administrations. The precise effective amount needed for a subjectwill depend upon, for example, the subject's size, health and age, thenature and extent of cognitive impairment or other symptoms of thecondition being treated, such as neurodegeneration (such as Alzheimer'sdisease), pain and traumatic brain injury, the therapeutics orcombination of therapeutics selected for administration, and the mode ofadministration. The skilled worker can readily determine the effectiveamount for a given situation by routine experimentation.

“Ligand” as used herein refers to any molecule that is capable ofspecifically binding to another molecule, such as the P₂Y₆ receptor. Theterm “ligand” includes both agonists and antagonists. “Agonist” means anagent which, when interacting, either directly or indirectly, with abiologically active molecule (e.g. an enzyme or a receptor) causes anincrease in the biological activity thereof. “Antagonist” means an agentwhich, when interacting, either directly or indirectly, with abiologically active molecule(s) (e.g. an enzyme or a receptor) causes adecrease in the biological activity thereof. In certain embodiments, thecompounds, salts and prodrugs of the present disclosure agonize P₂Y₆receptor activity.

The term “aliphatic” as used herein means a straight chained or branchedalkyl, alkenyl or alkynyl. It is understood that alkenyl or alkynylembodiments need at least two carbon atoms in the aliphatic chain.Aliphatic groups typically contains from 1 (or 2) to 12 carbons, such asfrom 1 (or 2) to 4 carbons.

The term “aryl” as used herein means a monocyclic or bicycliccarbocyclic aromatic ring system. Phenyl is an example of a monocyclicaromatic ring system. Bicyclic aromatic ring systems include systemswherein both rings are aromatic, e.g., naphthyl, and systems whereinonly one of the two rings is aromatic, e.g., tetralin.

The term “heterocyclic” as used herein means a monocyclic or bicyclicnon-aromatic ring system having 1 to 3 heteroatom or heteroatom groupsin each ring selected from O, N, NH, S, SO, or SO₂ in a chemicallystable arrangement. In a bicyclic non-aromatic ring system embodiment of“heterocyclyl”, one or both rings may contain said heteroatom orheteroatom groups. In another heterocyclic ring system embodiment, anon-aromatic heterocyclic ring may optionally be fused to an aromaticcarbocycle.

Examples of heterocyclic rings include 3-1H-benzimidazol-2-one,3-(1-alkyl)-benzimidazol-2-one, 2-tetrahydrofuranyl,3-tetrahydrofuranyl, 2-tetrahydrothiophenyl, 3-tetrahydrothiophenyl,2-morpholino, 3-morpholino, 4-morpholino, 2-thiomorpholino,3-thiomorpholino, 4-thiomorpholino, 1-pyrrolidinyl, 2-pyrrolidinyl,3-pyrrolidinyl, 1-tetrahydropiperazinyl, 2-tetrahydropiperazinyl,3-tetrahydropiperazinyl, 1-piperidinyl, 2-piperidinyl, 3-piperidinyl,1-pyrazolinyl, 3-pyrazolinyl, 4-pyrazolinyl, 5-pyrazolinyl,1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-piperidinyl,2-thiazolidinyl, 3-thiazolidinyl, 4-thiazolidinyl, 1-imidazolidinyl,2-imidazolidinyl, 4-imidazolidinyl, 5-imidazolidinyl, indolinyl,tetrahydroquinolinyl, tetrahydroisoquinolinyl, benzothiolane,benzodithiane, and 1,3-dihydro-imidazol-2-one.

The term “heteroaryl” as used herein means a monocyclic or bicyclicaromatic ring system having 1 to 3 heteroatom or heteroatom groups ineach ring selected from O, N, NH or S in a chemically stablearrangement. In such a bicyclic aromatic ring system embodiment of“heteroaryl” both rings may be aromatic; and one or both rings maycontain said heteroatom or heteroatom groups.

Examples of heteroaryl rings include 2-furanyl, 3-furanyl, N-imidazolyl,2-imidazolyl, 4-imidazolyl, 5-imidazolyl, benzimidazolyl, 3-isoxazolyl,4-isoxazolyl, 5-isoxazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl,N-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, pyridazinyl (e.g.,3-pyridazinyl), 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, tetrazolyl (e.g.,5-tetrazolyl), triazolyl (e.g., 2-triazolyl and 5-triazolyl), 2-thienyl,3-thienyl, benzofuryl, benzothiophenyl, indolyl (e.g., 2-indolyl),pyrazolyl (e.g., 2-pyrazolyl), isothiazolyl, 1,2,3-oxadiazolyl,1,2,5-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,3-triazolyl,1,2,3-thiadiazolyl, 1,3,4-thiadiazolyl, 1,2,5-thiadiazolyl, purinyl,pyrazinyl, 1,3,5-triazinyl, quinolinyl (e.g., 2-quinolinyl,3-quinolinyl, 4-quinolinyl), and isoquinolinyl (e.g., 1-isoquinolinyl,3-isoquinolinyl, or 4-isoquinolinyl).

The term “cycloalkyl or cycloalkenyl” refers to a monocyclic or fused orbridged bicyclic carbocyclic ring system that is not aromatic.Cycloalkenyl rings have one or more units of unsaturation. Exemplarycycloalkyl or cycloalkenyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cyclohexenyl, cycloheptyl, cycloheptenyl,norbomyl, adamantyl and decalinyl.

As used herein, the carbon atom designations may have the indicatedinteger and any intervening integer. For example, the number of carbonatoms in a (C1-C4)-alkyl group is 1, 2, 3, or 4. It should be understoodthat these designation refer to the total number of atoms in theappropriate group. For example, in a (C3-C10)-heterocyclyl the totalnumber of carbon atoms and heteroatoms is 3 (as in aziridine), 4, 5, 6(as in morpholine), 7, 8, 9, or 10.

“Pharmaceutically acceptable salt” or “salt” is used herein to refer toan agent or a compound or a prodrug according to the disclosure that isa therapeutically active, non-toxic base and acid salt form of thecompounds or prodrugs. The acid addition salt form of a compound thatoccurs in its free form as a base can be obtained by treating said freebase form with an appropriate acid such as an inorganic acid, forexample, a hydrohalic such as hydrochloric or hydrobromic, sulfuric,nitric, phosphoric and the like; or an organic acid, such as, forexample, acetic, hydroxyacetic, propanoic, lactic, pyruvic, malonic,succinic, maleic, fumaric, malic, tartaric, citric, methanesulfonic,ethanesulfonic, benzenesulfonic, p-toluenesulfonic, cyclic, salicylic,p-aminosalicylic, pamoic and the like. See, e.g., WO 01/062726.

Compounds containing acidic protons may be converted into theirtherapeutically active, non-toxic base addition salt form, e. g. metalor amine salts, by treatment with appropriate organic and inorganicbases. Appropriate base salt forms include, for example, ammonium salts,alkali and earth alkaline metal salts, e. g., lithium, sodium,potassium, magnesium, calcium salts and the like, salts with organicbases, e. g. N-methyl-D-glucamine, hydrabamine salts, and salts withamino acids such as, for example, arginine, lysine and the like.Conversely, said salt forms can be converted into the free forms bytreatment with an appropriate base or acid. Compounds or prodrugs andtheir salts can be in the form of a solvate, which is included withinthe scope of the present disclosure. Such solvates include for examplehydrates, alcoholates and the like. See, e.g., WO 01/062726.

Many of the compounds, salts or prodrugs useful in the methods andcompositions of this disclosure have at least one stereogenic center intheir structure. This stereogenic center may be present in a R or a Sconfiguration, said R and S notation is used in correspondence with therules described in Pure Appl. Chem. (1976), 45, 11-30. The disclosurealso relates to all stereoisomeric forms such as enantiomeric anddiastereoisomeric forms of the compounds, salts, prodrugs or mixturesthereof (including all possible mixtures of stereoisomers). See, e.g.,WO 01/062726.

Furthermore, certain compounds which contain alkenyl groups may exist asZ (zusammen) or E (entgegen) isomers. In each instance, the disclosureincludes both mixture and separate individual isomers. Multiplesubstituents on a piperidinyl or the azepanyl ring can also stand ineither cis or trans relationship to each other with respect to the planeof the piperidinyl or the azepanyl ring. Some of the compounds may alsoexist in tautomeric forms. Such forms, although not explicitly indicatedin the formulae described herein, are intended to be included within thescope of the present disclosure. With respect to the methods andcompositions of the present disclosure, reference to a compound orcompounds is intended to encompass that compound in each of its possibleisomeric forms and mixtures thereof unless the particular isomeric formis referred to specifically. See, e.g., WO 01/062726.

“Prodrug” or “pharmaceutically acceptable prodrug” refers to a compoundthat is metabolized, for example hydrolyzed or oxidized, in the hostafter administration to form the compound of the present disclosure(e.g., compounds of formula I, I-A, or II). Typical examples of prodrugsinclude compounds that have biologically labile or cleavable(protecting) groups on a functional moiety of the active compound.Prodrugs include compounds that can be oxidized, reduced, aminated,deaminated, hydroxylated, dehydroxylated, hydrolyzed, dehydrolyzed,alkylated, dealkylated, acylated, deacylated, phosphorylated, ordephosphorylated to produce the active compound. Examples of prodrugsusing ester or phosphoramidate as biologically labile or cleavable(protecting) groups are disclosed in U.S. Pat. Nos. 6,875,751,7,585,851, and 7,964,580, the disclosures of which are incorporatedherein by reference. The prodrugs of this disclosure are metabolized toproduce a compound of formula I or II, which are agonists of the P₂Y₆receptor.

The disclosure further provides pharmaceutical compositions comprisingone or more of the compounds, salts and prodrugs of the disclosuretogether with a pharmaceutically acceptable carrier or excipient.

B. UDP Derivatives and Compositions

The present disclosure provides a compound of formula I:

or a prodrug or salt thereof, wherein:

-   A is a 3- to 10-membered aromatic or non-aromatic ring having up to    5 heteroatoms independently selected from N, O, S, SO, or SO₂,    wherein the aromatic or non-aromatic ring is independently and    optionally substituted with one or more R⁷;-   X is independently selected from —O—, —S—, —N(R⁵)— and a    (C1-C3)-aliphatic group independently and optionally substituted    with one or more R⁴;-   Y is a bond or a (C1-C5)-aliphatic group independently and    optionally substituted with one or more R⁴;-   Z and W are each independently selected from ═O, ═S, ═N(R⁵), and    ═NOR⁵;-   R¹ is selected from:    -   —H, halogen, —OR⁵, —CN, —CF₃, —OCF₃ and a (C1-C6)-aliphatic        group optionally substituted with one or more R⁷;-   R² and R³ are each independently selected from:    -   —OR⁵, —SR⁵, —NR⁵R⁶, —OC(O)R⁵, —OC(O)NR⁵R⁶, and —OC(O)OR⁵;        preferably, R² and R³ are each independently selected from —OR⁵,        —SR⁵, —NR⁵R⁶ and —OC(O)R⁵;-   each occurrence of R⁴ is independently selected from:    -   halogen, —OR⁵, —NO₂, —CN, —CF₃, —OCF₃, —R⁵, 1,2-methylenedioxy,        1,2-ethylenedioxy, —N(R⁵)₂, —SR⁵, —SOR⁵, —SO₂R⁵, —SO₂N(R⁵)₂,        —SO₃R⁵, —C(O)R⁵, —C(O)C(O)R⁵, —C(O)CH₂C(O)R⁵, —C(S)R⁵, —C(S)OR⁵,        —C(O)OR⁵, —C(O)C(O)OR⁵, —C(O)C(O)N(R⁵)₂, —OC(O)R⁵, —C(O)N(R⁵)₂,        —OC(O)N(R⁵)₂, —C(S)N(R⁵)₂, —(CH₂)₀₋₂NHC(O)R⁵, —N(R⁵)N(R⁵)COR⁵,        —N(R⁵)N(R⁵)C(O)OR⁵, —N(R⁵)N(R⁵)CON(R⁵)₂, —N(R⁵)SO₂R⁵,        —N(R⁵)SO₂N(R⁵)₂, —N(R⁵)C(O)OR⁵, —N(R⁵)C(O)R⁵, —N(R⁵)C(S)R⁵,        —N(R⁵)C(O)N(R⁵)₂, —N(R⁵)C(S)N(R⁵)₂, —N(COR⁵)COR⁵, —N(OR⁵)R⁵,        —C(═NH)N(R⁵)₂, —C(O)N(OR⁵)R⁵, —C(═NOR⁵)R⁵, —OP(O)(OR⁵)₂,        —P(O)(R⁵)₂, —P(O)(OR⁵)₂, or —P(O)(H)(OR⁵);-   each occurrence of R⁵ is independently selected from:    -   H—,    -   (C1-C12)-aliphatic-,    -   (C3-C10)-cycloalkyl- or -cycloalkenyl-,    -   [(C3-C10)-cycloalkyl or -cycloalkenyl]-(C1-C12)-aliphatic-,    -   (C6-C10)-aryl-,    -   (C6-C10)-aryl-(C1-C12)aliphatic-,    -   (C3-C10)-heterocyclyl-,    -   (C6-C10)-heterocyclyl-(C1-C12)aliphatic-,    -   (C5-C10)-heteroaryl-, and    -   (C5-C10)-heteroaryl-(C1-C12)-aliphatic-;    -   wherein two R⁵ groups bound to the same atom optionally form a        3- to 10-membered aromatic or non-aromatic ring having up to 3        heteroatoms independently selected from N, O, S, SO, or SO₂,        wherein said ring is optionally fused to a (C6-C10)aryl,        (C5-C10)heteroaryl, (C3-C10)cycloalkyl, or a        (C3-C10)heterocyclyl; and    -   wherein each R⁵ group is independently and optionally        substituted with one or more R⁷;-   R⁶ is selected from:    -   —R⁵, —C(O)R⁵, —C(O)OR⁵, —C(O)N(R⁵)₂ and —S(O)₂R⁵;-   each occurrence of R⁷ is independently selected from:    -   halogen, —OR⁸, —NO₂, —CN, —CF₃, —OCF₃, —R⁸, oxo, thioxo,        1,2-methylenedioxy, 1,2-ethylenedioxy, —N(R⁸)₂, —SR⁸, —SOR⁸,        —SO₂R⁸, —SO₂N(R⁸)₂, —SO₃R⁸, —C(O)R⁸, —C(O)C(O)R⁸,        —C(O)CH₂C(O)R⁸, —C(S)R⁸, —C(S)OR⁸, —C(O)OR⁸, —C(O)C(O)OR⁸,        —C(O)C(O)N(R⁸)₂, —OC(O)R⁸, —C(O)N(R⁸)₂, —OC(O)N(R⁸)₂,        —C(S)N(R⁸)₂, —(CH₂)₀₋₂NHC(O)R⁸, —N(R⁸)N(R⁸)COR⁸,        —N(R⁸)N(R⁸)C(O)OR⁸, —N(R⁸)N(R⁸)CON(R⁸)₂, —N(R⁸)SO₂R⁸,        —N(R⁸)SO₂N(R⁸)₂, —N(R⁸)C(O)OR⁸, —N(R⁸)C(O)R⁸, —N(R⁸)C(S)R⁸,        —N(R⁸)C(O)N(R⁸)₂, —N(R⁸)C(S)N(R⁸)₂, —N(COR⁸)COR⁸, —N(OR⁸)R⁸,        —C(═NH)N(R⁸)₂, —C(O)N(OR⁸)R⁸, —C(═NOR⁸)R⁸, —OP(O)(OR⁸)₂,        —P(O)(R⁸)₂, —P(O)(OR⁸)₂ or —P(O)(H)(OR⁸);-   each occurrence of R⁸ is independently selected from:    -   H— and (C1-C6)-aliphatic-.

In some embodiments, the salt is a pharmaceutically acceptable salt of acompound of formula I, such as a sodium salt.

In certain embodiments of compound of formula I, A is a(C5-C10)-aromatic ring having up to 5 heteroatoms independently selectedfrom N, O and S, wherein the aromatic ring is independently andoptionally substituted with one or more R⁷. In some embodiments, A is anoptionally substituted 5- or 6-membered aromatic ring having up to 2heteroatoms selected from N, O and S. In some embodiments, A is anoptionally substituted bi-cyclic aromatic ring having up to 4heteroatoms selected from N, O and S.

In some embodiments, A may be an optionally substituted 5- or 6-memberedaromatic group selected from:

wherein A is optionally further substituted with one or more R⁷.

In some embodiments of formula I, A is an optionally substituted 9- or10-membered bicyclic aromatic ring having up to 4 heteroatoms selectedfrom N, O and S. In some embodiments, A is an optionally substitutedbicyclic aromatic ring containing two fused 6-membered aromatic rings,wherein the optionally substituted bicyclic aromatic ring may contain upto 4 nitrogen atoms. In some embodiments, A is an optionally substitutedbicyclic aromatic ring containing one 6-membered aromatic ring fused toone 5-membered aromatic ring, wherein the optionally substitutedbicyclic aromatic ring may contain up to 4 heteroatoms selected from N,O and S. For example, A may be a bicyclic aromatic group selected from:

wherein A is optionally further substituted with one or more R⁷.

In some embodiments, A is an aromatic group selected from:

wherein A is optionally further substituted with one or more R⁷.

In certain embodiments, A is selected from:

wherein A is optionally further substituted with one or more R⁷.

In certain embodiments, A is selected from:

wherein A is optionally further substituted with one or more R⁷.

In certain embodiments, A is selected from:

wherein A is optionally further substituted with one or more R⁷.

In some embodiments, A is

optionally further substituted with one or more R⁷.

In some embodiments, A is

optionally further substituted with one or more R⁷.

In certain embodiments, A is

optionally further substituted with one or more R⁷. In certainembodiments, A is

optionally further substituted with one or more R⁷, wherein R⁸ is notmethyl.

In another embodiment, A is

optionally substituted with one or more R⁷. In some of the aboveembodiments of A, each occurrence of R⁷ is independently selected fromhalogen, —CF₃, —OCF₃, —C1-C4 aliphatic (e.g., —C1-C4 alkyl), and—O(C1-C4 aliphatic) (e.g., —O(C1-C4 alkyl)).

In certain embodiments, the present disclosure provides compounds offormula I, where X is —O—.

In some embodiments, the present disclosure also provides compounds offormula I, where R¹ is —H, bromine, iodine, methyl, ethyl or —CF₃. Insome embodiments, R¹ is —H.

According to certain embodiments, the present disclosure provides acompound of formula I, where Z is ═O or ═S. In some embodiments, Z is═O.

In some embodiments, the compound of the present disclosure has a W thatis ═O or ═S. In some embodiments, W is ═O.

According to certain embodiments, the present disclosure provides acompound of formula I, where Y is a C1-aliphatic group optionallysubstituted with one or more R⁴. For example, Y is —CH₂—. In someembodiments, Y is a C2-aliphatic group optionally substituted with oneor more R⁴. In some embodiments, Y is —CH₂—C(R⁴)₂—, such as —CH₂—CH₂—.In another embodiment, Y is —CH₂—C(R⁴)₂—, where each R⁴ is independentlyselected from halogen. In some embodiments, Y is —CH₂—C(R⁴)₂—, whereboth occurrences of R⁴ are —F. In another embodiment, Y is —CH₂—C(R⁴)₂—,where each occurrence of R⁴ is independently a (C1-C3)-aliphatic group.In yet another embodiment, Y is —CH₂—C(R⁴)₂—, where both occurrences ofR⁴ are —CH₃.

In some embodiments, the present disclosure provides a compound offormula I, where R² and R³ are each independently —OR⁵. In someembodiments, R² is —OH. In another embodiment, R³ is —OH.

The disclosure also includes various combinations of A, X, Y, Z, W, R¹,R² and R³ as described above. These combinations can in turn be combinedwith any or all of the values of the other variables described above.For example, in some embodiments, Y is a C1- or C2-aliphatic groupoptionally substituted with one or more R⁴ and X is —O—. In anotherembodiment, Y is a C1- or C2-aliphatic group optionally substituted withone or more R⁴; X is —O—; and Z is ═O. In another embodiment, Y is a C1-or C2-aliphatic group optionally substituted with one or more R⁴; X is—O—; Z is ═O; and W is ═O. In yet another embodiment, Y is a C1- orC2-aliphatic group optionally substituted with one or more R⁴; X is —O—;Z is ═O; W is ═O; and R¹ is selected from —H, bromine, iodine, methyl,ethyl, and —CF₃, for example, R¹ is —H. In a further embodiment, Y is aC1- or C2-aliphatic group optionally substituted with one or more R⁴; Xis —O—; Z is ═O; W is ═O; and R¹ is selected from —H, bromine, iodine,methyl, ethyl, and —CF₃; and A is selected from the following groups:

wherein A is optionally further substituted with one or more R⁷, forexample, A is optionally substituted

In a further embodiment, Y is a C1- or C2-aliphatic group optionallysubstituted with one or more R⁴; X is —O—; Z is ═O; W is ═O; and R¹ isselected from —H, bromine, iodine, methyl, ethyl, and —CF₃; A isselected from the following group:

wherein A is optionally further substituted with one or more R⁷; and R²and R³ are each independently —OR⁵, for example, R² and R³ are eachindependently —OH. In some of the above embodiments, A is

optionally further substituted with one or more R⁷. In some of the aboveembodiments, A is

optionally further substituted with one or more R⁷, wherein R⁸ is notmethyl. In another embodiment, Y is a C1- or C2-aliphatic groupoptionally substituted with one or more R⁴; X is —O—; Z is ═O; W is ═O;and R¹ is selected from —H, bromine, iodine, methyl, ethyl, and —CF₃;and A is selected from the following groups:

wherein A is optionally further substituted with one or more R⁷, forexample, A is optionally substituted

In a further embodiment, Y is a C1- or C2-aliphatic group optionallysubstituted with one or more R⁴; X is —O—; Z is ═O; W is ═O; and R¹ isselected from —H, bromine, iodine, methyl, ethyl, and —CF₃; A isselected from the following groups:

wherein A is optionally further substituted with one or more R⁷;and R² and R³ are each independently —OR⁵, for example, R² and R³ areeach independently —OH. In some of the above embodiments, eachoccurrence of R⁷ is independently selected from halogen, —CF₃, —OCF₃,—C1-C4 aliphatic (e.g., —C1-C4 alkyl), and —O(C1-C4 aliphatic) (e.g.,—O(C1-C4 alkyl)).

The present disclosure also provides a compound of formula I-A:

or a salt thereof, wherein:A is selected from:

-   -   a phenyl group;    -   a naphthyl group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O, and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, and S;    -   wherein A is optionally further substituted with 1, 2, or 3        substituents independently selected from the group consisting of        halogen, hydroxyl, (C1-C6)-alkyl, (C1-C6)-alkoxyl, and        (C1-C6)-haloalkoxyl;        Y is a (C1-C6)-alkylene optionally substituted with halogen; and        R¹ is —H, halogen, or a (C1-C6)-aliphatic group optionally        substituted with one or more halogen.

In certain embodiments, A is a 5- to 10-membered heteroaryl group havingup to 3 heteroatoms independently selected from N, O, and S. In certainother embodiments, A is

optionally substituted by halogen, hydroxyl, (C1-C6)-alkyl,(C1-C6)-alkoxyl, or (C1-C6)-haloalkoxyl. In certain other embodiments, Ais

In certain other embodiments, R¹ is hydrogen or methyl.

The present disclosure also provides a compound of formula II:

or a prodrug or salt thereof, wherein:

-   A is selected from:    -   a phenyl group that is substituted with at least one        (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;    -   wherein A is optionally further substituted with one or more R⁴;-   X is independently selected from —O—, —S—, —N(R⁵)— and a    (C1-C3)-aliphatic group independently and optionally substituted    with one or more R⁴;-   Y¹ is a (C1-C5)-aliphatic group substituted with at least one oxo    and further independently and optionally substituted with one or    more R⁴;-   Z and W are each independently selected from ═O, ═S, ═N(R⁵), and    ═NOR⁵;-   R¹ is selected from:    -   —H, halogen, —OR⁵, —CN, —CF₃, —OCF₃ and a        (C1-C6)-aliphatic-group optionally substituted with one or more        R⁴;-   R² and R³ are each independently selected from —OR⁵, —SR⁵, —NR⁵R⁶,    —OC(O)R⁵, —OC(O)NR⁵R⁶, and —OC(O)OR⁵; preferably, R² and R³ are each    independently selected from —OR⁵, —SR⁵, —NR⁵R⁶ and —OC(O)R⁵;-   each occurrence of R⁴ is independently selected from:    -   halogen, —OR⁵, —NO₂, —CN, —CF₃, —OCF₃, —R⁵, oxo, thioxo,        1,2-methylenedioxy, 1,2-ethylenedioxy, —N(R⁵)₂, —SR⁵, —SOR⁵,        —SO₂R⁵, —SO₂N(R⁵)₂, —SO₃R⁵, —C(O)R⁵, —C(O)C(O)R⁵,        —C(O)CH₂C(O)R⁵, —C(S)R⁵, —C(S)OR⁵, —C(O)OR⁵, —C(O)C(O)OR⁵,        —C(O)C(O)N(R⁵)₂, —OC(O)R⁵, —C(O)N(R⁵)₂, —OC(O)N(R⁵)₂,        —C(S)N(R⁵)₂, —(CH₂)₀₋₂NHC(O)R⁵, —N(R⁵)N(R⁵)COR⁵,        —N(R⁵)N(R⁵)C(O)OR⁵, —N(R⁵)N(R⁵)CON(R⁵)₂, —N(R⁵)SO₂R⁵,        —N(R⁵)SO₂N(R⁵)₂, —N(R⁵)C(O)OR⁵, —N(R⁵)C(O)R⁵, —N(R⁵)C(S)R⁵,        —N(R⁵)C(O)N(R⁵)₂, —N(R⁵)C(S)N(R⁵)₂, —N(COR⁵)COR⁵, —N(OR⁵)R⁵,        —C(═NH)N(R⁵)₂, —C(O)N(OR⁵)R⁵, —C(═NOR⁵)R⁵, —OP(O)(OR⁵)₂,        —P(O)(R⁵)₂, —P(O)(OR⁵)₂, or —P(O)(H)(OR⁵);-   each occurrence of R⁵ is independently selected from:    -   H—,    -   (C1-C12)-aliphatic-,    -   (C3-C10)-cycloalkyl- or -cycloalkenyl-,    -   [(C3-C10)-cycloalkyl or -cycloalkenyl]-(C1-C12)-aliphatic-,    -   (C6-C10)-aryl-,    -   (C6-C10)-aryl-(C1-C12)aliphatic-,    -   (C3-C10)-heterocyclyl-,    -   (C6-C10)-heterocyclyl-(C1-C12)aliphatic-,    -   (C5-C10)-heteroaryl-, and    -   (C5-C10)-heteroaryl-(C1-C12)-aliphatic-;    -   wherein two R⁵ groups bound to the same atom optionally form a        3- to 10-membered aromatic or non-aromatic ring having up to 3        heteroatoms independently selected from N, O, S, SO, or SO₂,        wherein said ring is optionally fused to a (C6-C10)aryl,        (C5-C10)heteroaryl, (C3-C10)cycloalkyl, or a        (C3-C10)heterocyclyl; and    -   wherein each R⁵ group is independently and optionally        substituted with one or more R⁷;-   R⁶ is selected from:    -   —R⁵, —C(O)R⁵, —C(O)OR⁵, —C(O)N(R⁵)₂ and —S(O)₂R⁵;-   each occurrence of R⁷ is independently selected from:    -   halogen, —OR⁸, —NO₂, —CN, —CF₃, —OCF₃, —R⁸, oxo, thioxo,        1,2-methylenedioxy, 1,2-ethylenedioxy, —N(R⁸)₂, —SR⁸, —SOR⁸,        —SO₂R⁸, —SO₂N(R⁸)₂, —SO₃R⁸, —C(O)R⁸, —C(O)C(O)R⁸,        —C(O)CH₂C(O)R⁸, —C(S)R⁸, —C(S)OR⁸, —C(O)OR⁸, —C(O)C(O)OR⁸,        —C(O)C(O)N(R⁸)₂, —OC(O)R⁸, —C(O)N(R⁸)₂, —OC(O)N(R⁸)₂,        —C(S)N(R⁸)₂, —(CH₂)₀₋₂NHC(O)R⁸, —N(R⁸)N(R⁸)COR⁸,        —N(R⁸)N(R⁸)C(O)OR⁸, —N(R⁸)N(R⁸)CON(R⁸)₂, —N(R⁸)SO₂R⁸,        —N(R⁸)SO₂N(R⁸)₂, —N(R⁸)C(O)OR⁸, —N(R⁸)C(O)R⁸, —N(R⁸)C(S)R⁸,        —N(R⁸)C(O)N(R⁸)₂, —N(R⁸)C(S)N(R⁸)₂, —N(COR⁸)COR⁸, —N(OR⁸)R⁸,        —C(═NH)N(R⁸)₂, —C(O)N(OR⁸)R⁸, —C(═NOR⁸)R⁸, —OP(O)(OR⁸)₂,        —P(O)(R⁸)₂, —P(O)(OR⁸)₂, or —P(O)(H)(OR⁸);-   each occurrence of R⁸ is independently selected from:    -   H— and (C1-C6)-aliphatic-.

In some embodiments, the salt is a pharmaceutically acceptable salt of acompound of formula II, such as a sodium salt.

In certain embodiments of compound of formula II, A is a phenyl groupthat is substituted with at least one (C1-C5)-aliphatic group orhalogen; a naphthalene group; or a 5- to 10-membered heteroaryl grouphaving up to 5 heteroatoms independently selected from N, O and S,wherein A is optionally further substituted with one or more R⁴. Forexample, A is selected from the following groups:

where A is optionally substituted with one or more R⁴.

In certain embodiments of compound of formula II, A is a(C5-C10)-aromatic ring having up to 5 heteroatoms independently selectedfrom N, O and S, wherein the aromatic ring is independently andoptionally substituted with one or more R⁴. In Some embodiments, A is anoptionally substituted 5- or 6-membered aromatic ring having up to 2heteroatoms selected from N, O and S. For example, A is an aromaticgroup selected from:

wherein A is optionally further substituted with one or more R⁴.

In some embodiments of formula II, A is an optionally substituted 9- or10-membered bicyclic aromatic ring having up to 4 heteroatoms selectedfrom N, O and S. In some embodiments, A is an optionally substitutedbicyclic aromatic ring containing two fused 6-membered aromatic rings,wherein the optionally substituted bicyclic aromatic ring may contain upto 4 nitrogen atoms. In some embodiments, A is an optionally substitutedbicyclic aromatic ring containing one 6-membered aromatic ring fused toone 5-membered aromatic ring, wherein the optionally substitutedbicyclic aromatic ring may contain up to 4 heteroatoms selected from N,O and S. For example, A may be a bicyclic aromatic group selected from:

wherein A is optionally further substituted with one or more R⁴.

In some embodiments of compound of formula II, A is selected from thefollowing groups:

where A is optionally substituted with one or more R⁴.

In such embodiments, A is one of the following groups:

where A is optionally further substituted with one or more R⁴.

In some embodiments, A is a bicyclic aromatic group selected from:

wherein A is optionally further substituted with one or more R⁴.

In some embodiments, A is selected from:

where A is optionally further substituted with one or more R⁴.

In some embodiments, A is selected from:

where A is optionally further substituted with one or more R⁴.

In some embodiments, A is

where A is optionally further substituted with one or more R⁴.

In some embodiments, A is

where A is optionally further substituted with one or more R⁴.

In some embodiments, A is

optionally further substituted with one or more R⁴. In some embodiments,A is

optionally further substituted with one or more R⁴, wherein R⁸ is notmethyl.

In a further embodiment, A is

optionally substituted with one or more R⁴. In some of the aboveembodiments of A, each occurrence of R⁴ is independently selected fromhalogen, —CF₃, —OCF₃, —C1-C4 aliphatic (e.g., —C1-C4 alkyl), and—O(C1-C4 aliphatic) (e.g., —O(C1-C4 alkyl)).

In some embodiments, Y¹ is a C2-aliphatic group substituted with atleast one oxo and optionally further substituted with one or more R⁴,and A is selected from:

a phenyl group that is substituted with at least one (C1-C5)-aliphaticgroup or halogen;

a naphthalene group; and

a 6-membered monocyclic or a 9- to 10-membered bicyclic heteroaryl grouphaving up to 5 heteroatoms independently selected from N, O and S,wherein the bicyclic heteroaryl group has a 6-membered aryl orheteroaryl ring that is directly connected to Y¹;

wherein A is optionally further substituted with one or more R⁴. In somesuch embodiments, Y¹ is a C2-aliphatic group substituted with one oxo,and A is selected from:

wherein A is optionally further substituted with one or more R⁴.

According to certain embodiments, the present disclosure provides acompound of formula II, where X is —O—.

In some embodiments of the compound of formula II, R¹ is —H, bromine,iodine, methyl, ethyl or —CF₃. In some embodiments, R¹ is —H.

According to certain embodiments, the present disclosure also provides acompound of formula II, where Z is ═0 or ═S. In some embodiments, Z is═O.

In some embodiments of the compound of formula II, W is ═O or ═S. Insome embodiments, W is ═O.

According to certain embodiments, the present disclosure also provides acompound of formula II, where Y¹ is a C1-aliphatic group substitutedwith oxo. In some embodiments, Y¹ is a C2-aliphatic group substitutedwith at least one oxo and optionally further substituted with one ormore R⁴. In another embodiment, Y¹ is —C(O)—C(R⁴)₂— or —C(R⁴)₂—C(O)—,for example, —C(O)—CH₂— or —CH₂—C(O)—. In a further embodiment, Y¹ is—C(O)—C(R⁴)₂— or —C(R⁴)₂—C(O)—, where each R⁴ is independently selectedfrom halogen. For example, Y¹ is —C(O)—C(R⁴)₂— or —C(R⁴)₂—C(O)—, whereboth occurrences of R⁴ in are —F. In yet another embodiment, Y¹ is—C(O)—C(R⁴)₂— or —C(R⁴)₂—C(O)—, where each R⁴ is independently a(C1-C3)-aliphatic group. For example, Y¹ is —C(O)—C(R⁴)₂— or—C(R⁴)₂—C(O)—, where both occurrences of R⁴ are —CH₃.

In some embodiments of compound of formula II, R² and R³ are eachindependently —OR⁵. In some embodiments, R² is —OH. In anotherembodiment, R³ is —OH.

The disclosure also includes various combinations of A, X, Y¹, Z, W, R¹,R² and R³ as described above. These combinations can in turn be combinedwith any or all of the values of the other variables described above.For example, in some embodiments, Y is a C1-aliphatic group substitutedwith an oxo or a C2-aliphatic group substituted with at least one oxoand optionally further substituted with one or more R⁴ and X is —O—. Inanother embodiment, Y¹ is a C1-aliphatic group substituted with an oxoor a C2-aliphatic group substituted with at least one oxo and optionallyfurther substituted with one or more R⁴; X is —O—; and Z is ═O. Inanother embodiment, Y is a C1-aliphatic group substituted with an oxo ora C2-aliphatic group substituted with at least one oxo and optionallyfurther substituted with one or more R⁴; X is —O—; Z is ═O; and W is ═O.In yet another embodiment, Y¹ is a C1-aliphatic group substituted withan oxo or a C2-aliphatic group substituted with at least one oxo andoptionally further substituted with one or more R⁴; X is —O—; Z is ═O; Wis ═O; and R¹ is selected from —H, bromine, iodine, methyl, ethyl, and—CF₃, for example, R¹ is —H. In a further embodiment, Y¹ is aC1-aliphatic group substituted with an oxo or a C2-aliphatic groupsubstituted with at least one oxo and optionally further substitutedwith one or more R⁴; X is —O—; Z is ═O; W is ═O; and R¹ is selected from—H, bromine, iodine, methyl, ethyl, and —CF₃; and A is selected from thefollowing groups:

wherein A is optionally further substituted with one or more R⁴, forexample, A is optionally further substituted

In yet a further embodiment, Y¹ is a C1-aliphatic group substituted withan oxo or a C2-aliphatic group substituted with at least one oxo andoptionally further substituted with one or more R⁴; X is —O—; Z is ═O; Wis ═O; and R¹ is selected from —H, bromine, iodine, methyl, ethyl, and—CF₃; A is selected from the following group:

wherein A is optionally further substituted with one or more R⁴;and R² and R³ are each independently —OR⁵, for example, R² and R³ areeach independently —OH. In some of the above embodiments, A is

optionally further substituted with one or more R⁴. In some of the aboveembodiments, A is

optionally further substituted with one or more R⁴, wherein R⁸ is notmethyl. In a further embodiment, Y¹ is a C1-aliphatic group substitutedwith an oxo or a C2-aliphatic group substituted with at least one oxoand optionally further substituted with one or more R⁴; X is —O—; Z is═O; W is ═O; and R¹ is selected from —H, bromine, iodine, methyl, ethyl,and —CF₃; and A is selected from the following groups:

wherein A is optionally further substituted with one or more R⁴, forexample, A is optionally further substituted

In yet a further embodiment, Y¹ is a C1-aliphatic group substituted withan oxo or a C2-aliphatic group substituted with at least one oxo andoptionally further substituted with one or more R⁴; X is —O—; Z is ═O; Wis ═O; and R¹ is selected from —H, bromine, iodine, methyl, ethyl, and—CF₃; A is selected from the following group:

wherein A is optionally further substituted with one or more R⁴;and R² and R³ are each independently —OR⁵, for example, R² and R³ areeach independently —OH. In some of the above embodiments, eachoccurrence of R⁷ is independently selected from halogen, —CF₃, —OCF₃,—C1-C4 aliphatic (e.g., —C1-C4 alkyl), and —O(C1-C4 aliphatic) (e.g.,—O(C1-C4 alkyl)).

Examples of particular compounds of the present disclosure include:

or pharmaceutically acceptable salts thereof. In certain embodiments,the pharmaceutically acceptable salt is a sodium salt.

In another embodiment, the present disclosure provides a pharmaceuticalcomposition comprising a pharmaceutically acceptable carrier and acompound of formula I or II or pharmaceutically acceptable salt formthereof.

In another embodiment, the present disclosure provides a compounddescribed herein in isolated form, i.e., an isolated compound. Exemplaryembodiments are an isolated compound of formula I (including formulai-A), an isolated compound of formula II, or any of compounds 1-57 inisolated form, or an isolated prodrug and/or salt of any of theforegoing. The term “isolated” refers to material that is removed fromits original environment (e.g., the natural environment if it isnaturally occurring or a synthetic mixture if the material issynthesized in vitro or ex vivo). The isolated compound is desirablysubstantially pure, such as having a purity of at least about 80%, 85%,90%, 95%, or 99% by weight.

C. General Synthetic Methodology

The compounds of this disclosure may be prepared in general by methodsknown to those skilled in the art. Scheme 1 below illustrates a generalsynthetic route to the compounds of the present disclosure. Otherequivalent schemes, which will be readily apparent to the ordinaryskilled organic chemist, may alternatively be used to synthesize variousportions of the molecules as illustrated by the general scheme below.

D. Prodrugs of UDP Derivatives

The present disclosure provides a prodrug of a compound of formula I orII or pharmaceutically acceptable salt form thereof. In someembodiments, the prodrug of the instant application includesbiologically labile or cleavable protecting groups at one or bothphosphate groups of a compound of formula I or II, e.g., moieties thatare cleaved or hydrolyzed in the patient's body to generate the compoundof formula I or II or a salt thereof. In some embodiments, the prodrugsof the present disclosure can be oxidized, reduced, aminated,deaminated, hydroxylated, dehydroxylated, hydrolyzed, dehydrolyzed,alkylated, dealkylated, acylated, deacylated, phosphorylated, ordephosphorylated to produce the compound of formula I or II.

In certain embodiments, the prodrug includes two biologically labile orcleavable protecting groups on the terminal phosphate group of acompound of formula I or II. In other embodiments, the prodrug includesthree biologically labile or cleavable protecting groups on bothphosphate groups of a compound of formula I or II.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   A, X, Y, Z, W, R¹, R² and R³ are as defined above in formula I;-   each n is independently 0-4;-   each occurrence of R^(1a) is a group independently selected from    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁷ as defined above    in formula I; and-   each occurrence of R^(1a′) is independently selected from —H and R⁷    as defined above in formula I.

In some embodiments of prodrug-IA, at least one R^(1a) is an alkylgroup, such as methyl, ethyl, isopropyl or t-butyl. In some embodimentsof prodrug-IA, at least one R^(1a) is an optionally substituted phenyl.In preferred embodiments, n is 0. In certain embodiments of prodrug-IA,both occurrences of R^(1a) are the same.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   A, X, Y, Z, W, R¹, R² and R³ are as defined above in formula I;-   each occurrence of R^(1b) is a group independently selected from    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁷ as defined above    in formula I; and-   each occurrence of R^(1b′) is independently —H, —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl), or —(C3-C6)-cycloalkyl; preferably, each    occurrence of R^(1b′) is independently —H or —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl).

In some embodiments of prodrug-IB1 or prodrug-IB2, at least oneoccurrence of R^(1b) is an alkyl group, such as methyl, ethyl, isopropylor t-butyl. In some embodiments of prodrug-IB1 or prodrug-IB2, at leastone occurrence of R^(1b′) is —H. In certain embodiments of prodrug-IB1or prodrug-IB2, at least one occurrence of R^(1b′) is a —(C1-C6)-alkylgroup, such as methyl, ethyl or isopropyl. In some embodiments ofprodrug-IB1 or prodrug-IB2, all the occurrences of R^(1b) are the same.In some embodiments, all the occurrences of R^(1b′) are the same.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   A, X, Y, Z, W, R¹, R² and R³ are as defined above in formula I;-   each occurrence of R^(1c) is a group independently selected from    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁷ as defined above    in formula I; and-   each occurrence of R^(1c′) is independently —H, —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl), or —(C3-C6)-cycloalkyl; preferably, each    occurrence of R^(1c′) is independently —H or —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl).

In some embodiments of prodrug-IC1 or prodrug-IC2, at least oneoccurrence of R^(1c) is an alkyl group, such as methyl, ethyl, isopropylor t-butyl. In some embodiments of prodrug-IC1 or prodrug-IC2, at leastone occurrence of R^(1c′) is —H. In certain embodiments of prodrug-IC1or prodrug-IC2, at least one occurrence of R^(1c′) is a —(C1-C6)-alkylgroup, such as methyl, ethyl or isopropyl. In some embodiments ofprodrug-IC1 or prodrug-IC2, all the occurrences of R^(1c) are the same.In some embodiments, all the occurrences of R^(1c′) are the same.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   A, X, Y, Z, W, R¹, R² and R³ are as defined above in formula I;-   R^(1d) is a group selected from aliphatic (such as —(C1-C6)-alkyl),    heterocyclyl, cycloalkyl, cycloalkenyl, aryl and heteroaryl, wherein    said aliphatic, heterocyclyl, cycloalkyl, cycloalkenyl, aryl or    heteroaryl is unsubstituted or substituted with at least one R⁷ as    defined above in formula I;-   n is 0-5, preferably 0-2, most preferably 0; and-   each occurrence of R^(1d′) is independently selected from —H and R⁷    as defined above in formula I.

In some embodiments of prodrug-ID, R^(1d) is an alkyl group, such asmethyl, ethyl, isopropyl or t-butyl. In other embodiments of prodrug-ID,R^(1d) is an optionally substituted phenyl. In certain embodiments, n is0. In preferred embodiments where n is 1 or 2, all R^(1d′) are attachedto the carbon of the ring distal to the carbon bearing R^(1d)CO₂.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   A, X, Y, Z, W, R¹, R² and R³ are as defined above in formula I;-   n is 0-4; and-   each occurrence of R^(1e) is independently selected from —H and R⁷    as defined above in formula I.

In some embodiments of prodrug-IE, at least one occurrence of R^(1e) isa —(C1-C6)-alkyl group, such as methyl, ethyl, isopropyl or t-butyl. Insome embodiments of prodrug-IE, at least one occurrence of R^(1e) ishalogen, preferably —F or —Cl. In certain embodiments, n is 1. Incertain embodiments of prodrug-IE, n is 1 and R^(1e) is methyl.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   A, X, Y, Z, W, R¹, R² and R³ are as defined above in formula I;-   R^(1fa) and R^(1fb) each independently is a group selected from —H,    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁷ as defined above    in formula I; and-   R^(1f′) and R^(1f″) each independently is a group selected from —H,    —(C1-C6)-aliphatic (such as —(C1-C6)-alkyl) and —(C3-C6)-cycloalkyl;    preferably, R^(1f′) and R^(1f′) each independently is a group    selected from —H or —(C1-C6)-aliphatic (such as —(C1-C6)-alkyl).

In some embodiments of prodrug-IF, R^(1fa) is an alkyl group, such asmethyl, ethyl, isopropyl or t-butyl. In some embodiments of prodrug-IF,R^(1fb) is an optionally substituted phenyl. In some embodiments ofprodrug-IF, R^(1f′) is —H. In certain embodiments of prodrug-IF, R^(1f′)is a —(C1-C6)-alkyl group, such as methyl, ethyl or isopropyl. In someembodiments of prodrug-IF, R^(1f″) is —H. In certain embodiments ofprodrug-IF, R^(1f′) is a —(C1-C6)-alkyl group, such as methyl, ethyl orisopropyl, and R^(1f″) is —H.

In certain embodiments of the above prodrugs of compounds of formula I,i.e., prodrug-IA-prodrug-IF, A is a (C5-C10)-aromatic ring having up to5 heteroatoms independently selected from N, O and S, wherein thearomatic ring is independently and optionally substituted with one ormore R⁷. In some embodiments, A is an optionally substituted 5- or6-membered aromatic ring having up to 2 heteroatoms selected from N, Oand S. For example, A is an aromatic group selected from:

wherein A is optionally further substituted with one or more R⁷.

In certain embodiments of prodrug-IA-prodrug-IF, A is an optionallysubstituted 9- or 10-membered bicyclic aromatic ring having up to 4heteroatoms selected from N, O and S. In some embodiments, A is anoptionally substituted bicyclic aromatic ring containing two fused6-membered aromatic rings, wherein the optionally substituted bicyclicaromatic ring may contain up to 4 nitrogen atoms. In some embodiments, Ais an optionally substituted bicyclic aromatic ring containing one6-membered aromatic ring fused to one 5-membered aromatic ring, whereinthe optionally substituted bicyclic aromatic ring may contain up to 4heteroatoms selected from N, O and S. For example, A may be a bicyclicaromatic group selected from:

wherein A is optionally further substituted with one or more R⁷.

In certain above embodiments A is selected from:

wherein A is optionally further substituted with one or more R⁷.

In some of the above embodiments, A is

optionally further substituted with one or more R⁷.

In another embodiment, A is

optionally substituted with one or more R⁷. In some of the aboveembodiments of A, each occurrence of R⁷ is independently selected fromhalogen, —CF₃, —OCF₃, —C1-C4 aliphatic (e.g., —C1-C4 alkyl), and—O(C1-C4 aliphatic) (e.g., —O(C1-C4 alkyl)).

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   X, Y¹, Z, W, R¹, R² and R³ are as defined above in formula II;-   A is selected from:    -   a phenyl group that is unsubstituted or substituted with at        least one (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;    -   wherein A is optionally further substituted with one or more R⁴;-   each n is independently 0-4;-   each occurrence of R^(2a) is a group independently selected from    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁴ as defined above    in formula II; and-   each occurrence of R^(2a′) is independently selected from —H and R⁴    as defined above in formula II.

In some embodiments of prodrug-IIA, A is as defined above in formula II.In some embodiments of prodrug-IIA, at least one R^(2a) is an alkylgroup, such as methyl, ethyl, isopropyl or t-butyl. In some embodimentsof prodrug-IIA, at least one R^(2a) is an optionally substituted phenyl.In preferred embodiments, n is 0. In certain embodiments of prodrug-IIA,both occurrences of R^(2a) are the same.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   X, Y¹, Z, W, R¹, R² and R³ are as defined above in formula II;-   A is selected from:    -   a phenyl group that is unsubstituted or substituted with at        least one (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;-   wherein A is optionally further substituted with one or more R⁴;-   each occurrence of R^(2b) is a group independently selected from    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁴ as defined above    in formula II; and-   each occurrence of R^(2b′) is independently —H, —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl), or —(C3-C6)-cycloalkyl; preferably, each    occurrence of R^(2b′) is independently —H or —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl).

In some embodiments of prodrug-IIB1 or prodrug-IIB2, A is as definedabove in formula II. In some embodiments of prodrug-IIB1 orprodrug-IIB2, at least one occurrence of R^(2b) is an alkyl group, suchas methyl, ethyl, isopropyl or t-butyl. In some embodiments ofprodrug-IIB1 or prodrug-IIB2, at least one occurrence of R^(2b′) is —H.In certain embodiments of prodrug-IIB1 or prodrug-IIB2, at least oneoccurrence of R^(2b′) is a —(C1-C6)-alkyl group, such as methyl, ethylor isopropyl. In some embodiments of prodrug-IIB1 or prodrug-IIB2, allthe occurrences of R^(2b) are the same. In some embodiments, all theoccurrences of R^(2b′) are the same.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   X, Y¹, Z, W, R¹, R² and R³ are as defined above in formula II;-   A is selected from:    -   a phenyl group that is unsubstituted or substituted with at        least one (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;-   wherein A is optionally further substituted with one or more R⁴;-   each occurrence of R^(2c) is a group independently selected from    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁴ as defined above    in formula II; and-   each occurrence of R^(2c′) is independently —H, —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl), or —(C3-C6)-cycloalkyl; preferably, each    occurrence of R^(2c′) is independently —H or —(C1-C6)-aliphatic    (such as —(C1-C6)-alkyl).

In some embodiments of prodrug-IIC1 or prodrug-IIC2, A is as definedabove in formula II. In some embodiments of prodrug-IIC1 orprodrug-IIC2, at least one occurrence of R^(2c) is an alkyl group, suchas methyl, ethyl, isopropyl or t-butyl. In some embodiments ofprodrug-IIC1 or prodrug-IIC2, at least one occurrence of R^(2c′) is —H.In certain embodiments of prodrug-IIC1 or prodrug-IIC2, at least oneoccurrence of R^(2c′) is a —(C1-C6)-alkyl group, such as methyl, ethylor isopropyl. In some embodiments of prodrug-IIC1 or prodrug-IIC2, allthe occurrences of R^(2c) are the same. In some embodiments, all theoccurrences of R^(2c′) are the same.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   X, Y¹, Z, W, R¹, R² and R³ are as defined above in formula II;-   A is selected from:    -   a phenyl group that is unsubstituted or substituted with at        least one (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;-   wherein A is optionally further substituted with one or more R⁴;-   R^(2d) is a group selected from aliphatic (such as —(C1-C6)-alkyl),    heterocyclyl, cycloalkyl, cycloalkenyl, aryl and heteroaryl, wherein    said aliphatic, heterocyclyl, cycloalkyl, cycloalkenyl, aryl or    heteroaryl is unsubstituted or substituted with at least one R⁴ as    defined above in formula II;-   n is 0-5, preferably 0-2, most preferably 0; and-   each occurrence of R^(2d′) is independently selected from —H and R⁴    as defined above in formula II.

In some embodiments of prodrug-IID, A is as defined above in formula II.In some embodiments of prodrug-IID, R^(2d) is an alkyl group, such asmethyl, ethyl, isopropyl or t-butyl. In other embodiments ofprodrug-IID, R^(2d) is an optionally substituted phenyl. In certainembodiments, n is 0. In preferred embodiments where n is 1 or 2, allR^(2d′) are attached to the carbon of the ring distal to the carbonbearing R^(2d)CO₂.

In certain embodiments, the prodrug of the present disclosure has theformula:

or a salt thereof,wherein:

-   X, Y¹, Z, W, R¹, R² and R³ are as defined above in formula II;-   A is selected from:    -   a phenyl group that is unsubstituted or substituted with at        least one (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;-   wherein A is optionally further substituted with one or more R⁴;-   n is 0-4; and-   each occurrence of R^(2e) is independently selected from —H and R⁴    as defined above in formula II.

In some embodiments of prodrug-IIE, A is as defined above in formula II.In some embodiments of prodrug-IIE, at least one occurrence of R^(2e) isa —(C1-C6)-alkyl group, such as methyl, ethyl, isopropyl or t-butyl. Insome embodiments of prodrug-IIE, at least one occurrence of R^(2e) ishalogen, preferably —F or —Cl. In certain embodiments, n is 1. In someembodiments of prodrug-IIE, n is 1 and R^(2e) is methyl.

In certain embodiments, the prodrug of the present disclosure has theformula:

or salt thereof,wherein:

-   X, Y¹, Z, W, R¹, R² and R³ are as defined above in formula II;-   A is selected from:    -   a phenyl group that is unsubstituted or substituted with at        least one (C1-C5)-aliphatic group or halogen;    -   a naphthalene group;    -   a 5- to 10-membered heteroaryl group having up to 5 heteroatoms        independently selected from N, O and S; and    -   a 3- to 10-membered non-aromatic ring having up to 5 heteroatoms        independently selected from N, O, S, SO, or SO₂;-   wherein A is optionally further substituted with one or more R⁴;-   R^(2fa) and R^(2fb) each independently is a group selected from —H,    aliphatic (such as —(C1-C6)-alkyl), heterocyclyl, cycloalkyl,    cycloalkenyl, aryl and heteroaryl, wherein said aliphatic,    heterocyclyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl is    unsubstituted or substituted with at least one R⁴ as defined above    in formula II; and-   R^(2f′) and R^(2f″) each independently is a group selected from —H,    —(C1-C6)-aliphatic (such as —(C1-C6)-alkyl) and —(C3-C6)-cycloalkyl;    preferably, R^(2f′) and R^(2f″) each independently is a group    selected from —H or —(C1-C6)-aliphatic (such as —(C1-C6)-alkyl).

In some embodiments of prodrug-IIF, A is as defined above in formula II.In some embodiments of prodrug-IIF, R^(2fa) is an alkyl group, such asmethyl, ethyl, isopropyl or t-butyl. In some embodiments of prodrug-IIF,R^(2fb) is an optionally substituted phenyl. In some embodiments ofprodrug-IIF, R^(2f′) is —H. In certain embodiments of prodrug-IIF,R^(2f′) is a —(C1-C6)-alkyl group, such as methyl, ethyl or isopropyl.In some embodiments of prodrug-IIF, R^(2″) is —H. In certain embodimentsof prodrug-IIF, R^(2f′) is a —(C1-C6)-alkyl group, such as methyl, ethylor isopropyl, and R^(2″) is —H.

In certain embodiments of the above prodrugs of compounds of formula II,i.e., prodrug-IIA-prodrug-IIF, A is a phenyl group that is unsubstitutedor substituted with at least one (C1-C5)-aliphatic group or halogen; anaphthalene group; or a 5- to 10-membered heteroaryl group having up to5 heteroatoms independently selected from N, O and S, wherein A isoptionally further substituted with one or more R⁴. For example, A maybe selected from the following groups:

where A is optionally substituted with one or more R⁴.

In certain embodiments of prodrug-IIA-prodrug-IIF, A is a(C5-C10)-aromatic ring having up to 5 heteroatoms independently selectedfrom N, O and S, wherein the aromatic ring is independently andoptionally substituted with one or more R⁴. In some embodiments, A is anoptionally substituted 5- or 6-membered aromatic ring having up to 2heteroatoms selected from N, O and S. For example, A is an aromaticgroup selected from:

wherein A is optionally further substituted with one or more R⁴.

In certain embodiments of prodrug-IIA-prodrug-IIF, A is an optionallysubstituted 9- or 10-membered bicyclic aromatic ring having up to 4heteroatoms selected from N, O and S. In some embodiments, A is anoptionally substituted bicyclic aromatic ring containing two fused6-membered aromatic rings, wherein the optionally substituted bicyclicaromatic ring may contain up to 4 nitrogen atoms. In some embodiments, Ais an optionally substituted bicyclic aromatic ring containing one6-membered aromatic ring fused to one 5-membered aromatic ring, whereinthe optionally substituted bicyclic aromatic ring may contain up to 4heteroatoms selected from N, O and S. For example, A may be a bicyclicaromatic group selected from:

wherein A is optionally further substituted with one or more R⁴.

In some of the above embodiments, A is selected from:

where A is optionally further substituted with one or more R⁴.

In some embodiments, A is

where A is optionally further substituted with one or more R⁴.

In a further embodiment, A is

optionally substituted with one or more R⁴. In some of the aboveembodiments of A, each occurrence of R⁴ is independently selected fromhalogen, —CF₃, —OCF₃, —C1-C4 aliphatic (e.g., —C1-C4 alkyl), and—O(C1-C4 aliphatic) (e.g., —O(C1-C4 alkyl)).

For a compound of the formula I or II:

representative prodrugs of the present disclosure include:

or salts thereof. In some embodiments of the prodrug of the presentdisclosure, the salt is a sodium salt.

In another embodiment, the present disclosure provides a pharmaceuticalcomposition comprising a pharmaceutically acceptable carrier and aprodrug of a compound of formula I or II or pharmaceutically acceptablesalt form thereof.

The disclosure contemplates that any one or more of the foregoingaspects and embodiments (including compounds of all of the precedingformulae as well as their salts and prodrugs) can be combined with eachother and/or with any of the embodiments or features provided below.

E. Exemplary Uses

1. Neuronal Diseases/Disorders

In certain aspects, the compounds, salts and/or prodrugs thereof, andcompositions as described herein can be used to treat patients sufferingfrom P₂Y₆ receptor-related conditions or conditions that can beameliorated by modulating, for example, agonizing P₂Y₆ receptoractivity, such as neurodegenerative diseases, and traumatic ormechanical injury to the central nervous system (CNS), spinal cord orperipheral nervous system (PNS). Accordingly, the disclosurecontemplates methods of treating (decreasing the frequency or severityof or otherwise alleviating one or more symptoms of the condition) asubject in need thereof (e.g., a subject having any of the conditionsdescribed herein, including any of the neurodegenerative or neuronalconditions described herein) by administering a compound, salt and/orprodrug of the disclosure. Many of these, as well as other conditionsdescribed herein, are characterized by a level of cognitive impairmentand/or some decrease or loss of cognitive function. Cognitive functionand cognitive impairment are used as understood in the art. For example,cognitive function generally refers to the mental processes by which onebecomes aware of, perceives, or comprehends ideas. Cognitive functioninvolves all aspects of perception, thinking, learning, reasoning,memory, awareness, and capacity for judgment. Cognitive impairmentgenerally refers to conditions or symptoms involving problems withthought processes. This may manifest itself in one or more symptomsindicating a decrease in cognitive function, such as impairment ordecrease of higher reasoning skills, forgetfulness, impairments tomemory, learning disabilities, concentration difficulties, decreasedintelligence, and other reductions in mental functions.

Neurodegenerative disease typically involves reductions in the mass andvolume of the human brain, which may be due to the atrophy and/or deathof brain cells, which are far more profound than those in a healthyperson that are attributable to aging. Neurodegenerative diseases canevolve gradually, after a long period of normal brain function, due toprogressive degeneration (e.g., nerve cell dysfunction and death) ofspecific brain regions. Alternatively, neurodegenerative diseases canhave a quick onset, such as those associated with trauma or toxins. Theactual onset of brain degeneration may precede clinical expression bymany years. Examples of neurodegenerative diseases include, but are notlimited to, Alzheimer's disease (AD), Parkinson's disease (PD),Huntington's disease (HD), amyotrophic lateral sclerosis (ALS; LouGehrig's disease), diffuse Lewy body disease, chorea-acanthocytosis,primary lateral sclerosis, ocular diseases (ocular neuritis),chemotherapy-induced neuropathies (e.g., from vincristine, paclitaxel,bortezomib), diabetes-induced neuropathies and Friedreich's ataxia. P₂Y₆receptor-modulating compounds, salts and/or prodrugs thereof, of thepresent disclosure can be used to treat these disorders and others asdescribed below.

AD is a CNS disorder that results in memory loss, unusual behavior,personality changes, and a decline in thinking abilities. These lossesare related to the death of specific types of brain cells and thebreakdown of connections and their supporting network (e.g. glial cells)between them. The earliest symptoms include loss of recent memory,faulty judgment, and changes in personality. Without being bound bytheory, these changes in the brain and symptoms associated withcognitive impairment, including memory and learning impairment, arecaused, in whole or in part, by accumulation of beta amyloid and theresulting deposition of amyloid plaques. PD is a CNS disorder thatresults in uncontrolled body movements, rigidity, tremor, anddyskinesia, and is associated with the death of brain cells in an areaof the brain that produces dopamine. ALS (motor neuron disease) is a CNSdisorder that attacks the motor neurons, components of the CNS thatconnect the brain to the skeletal muscles.

HD is another neurodegenerative disease that causes uncontrolledmovements, loss of intellectual faculties, and emotional disturbance.Tay-Sachs disease and Sandhoff disease are glycolipid storage diseaseswhere GM2 ganglioside and related glycolipids substrates forβ-hexosaminidase accumulate in the nervous system and trigger acuteneurodegeneration.

It is well-known that apoptosis plays a role in AIDS pathogenesis in theimmune system. However, HIV-1 also induces neurological disease, whichcan be treated with P₂Y₆ receptor-modulating compounds, salts and/orprodrugs thereof, of the disclosure.

Neuronal loss is also a salient feature of prion diseases, such asCreutzfeldt-Jakob disease in human, BSE in cattle (mad cow disease),Scrapie Disease in sheep and goats, and feline spongiform encephalopathy(FSE) in cats. P₂Y₆ receptor-modulating compounds, salts and/or prodrugsthereof, as described herein, may be useful for treating or preventingneuronal loss due to these prion diseases.

In another embodiment, the compounds, salts and/or prodrugs thereof, asdescribed herein may be used to treat or prevent any disease or disorderinvolving axonopathy. Distal axonopathy is a type of peripheralneuropathy that results from some metabolic or toxic derangement ofperipheral nervous system (PNS) neurons. It is the most common responseof nerves to metabolic or toxic disturbances, and as such may be causedby metabolic diseases such as diabetes, renal failure, deficiencysyndromes such as malnutrition and alcoholism, or the effects of toxinsor drugs. Those with distal axonopathies usually present withsymmetrical glove-stocking sensory-motor disturbances. Deep tendonreflexes and autonomic nervous system (ANS) functions are also lost ordiminished in affected areas.

Diabetic neuropathies are neuropathic disorders that are associated withdiabetes mellitus. Relatively common conditions which may be associatedwith diabetic neuropathy include third nerve palsy; mononeuropathy;mononeuritis multiplex; diabetic amyotrophy; a painful polyneuropathy;autonomic neuropathy; and thoracoabdominal neuropathy.

Peripheral neuropathy is the medical term for damage to nerves of theperipheral nervous system, which may be caused either by diseases of thenerve or from the side-effects of systemic illness. Major causes ofperipheral neuropathy include seizures, nutritional deficiencies, andHIV, though diabetes is the most likely cause.

In an exemplary embodiment, a P₂Y₆ receptor-modulating compound, saltand/or prodrug thereof, as described herein may be used to treat orprevent multiple sclerosis (MS), including relapsing MS andmonosymptomatic MS, and other demyelinating conditions, such as, forexample, chronic inflammatory demyelinating polyneuropathy (CIDP), orsymptoms associated therewith.

In yet another embodiment, compounds, salts and/or prodrugs thereof, ofthe present disclosure may be used to treat trauma to the nerves,including, trauma due to disease, injury (including surgicalintervention), or environmental trauma (e.g., neurotoxins, alcoholism,etc.). In certain embodiments, compounds, salts and/or prodrugs thereof,of the present disclosure may be used to treat traumatic brain injury,such as to improve cognitive function in a subject suffering from atraumatic brain injury. Without being bound by theory, there is often anincrease in beta amyloid observed following traumatic brain injuries.The present disclosure provides methods suitable for enhancing clearanceof beta amyloid or otherwise reducing beta amyloid and/or plaque burdenin a subject.

Compounds, salts and/or prodrugs thereof, of the present disclosure mayalso be useful to prevent, treat, and alleviate symptoms of various PNSdisorders. The term “peripheral neuropathy” encompasses a wide range ofdisorders in which the nerves outside of the brain and spinalcord—peripheral nerves—have been damaged. Peripheral neuropathy may alsobe referred to as peripheral neuritis, or if many nerves are involved,the terms polyneuropathy or polyneuritis may be used.

PNS diseases treatable with P₂Y₆ receptor-modulating compounds, saltsand/or prodrugs thereof, as described herein, include: diabetes,leprosy, Charcot-Marie-Tooth disease, Guillain-Barré syndrome andBrachial Plexus Neuropathies (diseases of the cervical and firstthoracic roots, nerve trunks, cords, and peripheral nerve components ofthe brachial plexus).

In another embodiment, compounds, salts and/or prodrugs thereof, of thepresent disclosure may be used to treat or prevent a polyglutaminedisease. Exemplary polyglutamine diseases include Spinobulbar muscularatrophy (Kennedy disease), Huntington's Disease (HD),Dentatorubral-pallidoluysian atrophy (Haw River syndrome),Spinocerebellar ataxia type 1, Spinocerebellar ataxia type 2,Spinocerebellar ataxia type 3 (Machado-Joseph disease), Spinocerebellarataxia type 6, Spinocerebellar ataxia type 7, and Spinocerebellar ataxiatype 17.

In certain embodiments, the disclosure provides a method to treat acentral nervous system cell to prevent damage in response to a decreasein blood flow to the cell. Typically the severity of damage that may beprevented will depend in large part on the degree of reduction in bloodflow to the cell and the duration of the reduction. In some embodiments,apoptotic or necrotic cell death may be prevented. In still a furtherembodiment, ischemic-mediated damage, such as cytoxic edema or centralnervous system tissue anoxemia, may be prevented. In each embodiment,the central nervous system cell may be a spinal cell or a brain cell.

Another aspect encompasses administrating a compound, or salt and/orprodrug thereof, as described herein to a subject to treat a centralnervous system ischemic condition. A number of central nervous systemischemic conditions may be treated by the compounds, salts and/orprodrugs thereof, described herein.

In some embodiments, the ischemic condition is a stroke that results inany type of ischemic central nervous system damage, such as apoptotic ornecrotic cell death, cytoxic edema or central nervous system tissueanoxia. The stroke may impact any area of the brain or be caused by anyetiology commonly known to result in the occurrence of a stroke. In onealternative of this embodiment, the stroke is a brain stem stroke. Inanother alternative of this embodiment, the stroke is a cerebellarstroke. In still another embodiment, the stroke is an embolic stroke. Inyet another alternative, the stroke may be a hemorrhagic stroke. In afurther embodiment, the stroke is a thrombotic stroke.

In yet another aspect, compounds, salts and/or prodrugs thereof, of thedisclosure may be administered to reduce infarct size of the ischemiccore following a central nervous system ischemic condition. Moreover,compounds, salts and/or prodrugs thereof, of the present disclosure mayalso be beneficially administered to reduce the size of the ischemicpenumbra or transitional zone following a central nervous systemischemic condition.

In some embodiments, a combination drug regimen may include drugs orcompounds for the treatment or prevention of neurodegenerative disordersor secondary conditions associated with these conditions. Thus, acombination drug regimen may include one or more compounds, salts and/orprodrugs thereof, as described herein and one or moreanti-neurodegeneration agents.

In a particular embodiment, the disclosure provides methods for doingone or more of decreasing plaque burden, improving cognitive function,decreasing or delaying cognitive impairment, or improving hippocampallong term potentiation by administering to a subject in need thereof aP₂Y₆ receptor-modulating compound, salts and/or prodrugs thereof. Thesemethods may also be used for one or more of enhancing beta amyloidclearance, increasing synaptic plasticity, or improving or restoringmemory. The foregoing are exemplary of beneficial results that wouldhelp alleviate (e.g., treat) one or more symptoms of conditionsassociated with cognitive impairment. Exemplary conditions include AD,traumatic brain injury, and Down Syndrome, as well as other neurologicaland neurodegenerative diseases. Moreover, the disclosure contemplatesthe alleviation of symptoms in conditions and scenarios associated withmilder forms of cognitive impairment, such as age-related dementia, mildcognitive impairment, and even to improve memory and cognitive functionthat typically declines, even in relatively healthy individuals, as partof the normal aging process. Exemplary such agonists, salts and/orprodrugs thereof, are described herein, and the disclosure contemplatesthat any such compounds, salts and/or prodrugs thereof can be used inthe treatment of any of the conditions described herein. Regardless ofwhether one of the agonists described herein are used or whether anotheragonist is used, the disclosure contemplates that the agonist may beformulated in a pharmaceutically acceptable carrier and administered byany suitable route of administration. These methods are of particularuse when the subject in need thereof has Alzheimer's disease. It isunderstood by those of skill in the art that definitive diagnosis ofAlzheimer's disease is difficult and may require post-mortemexamination. Thus, in this context and in the context of the presentdisclosure, having Alzheimer's disease is used to refer to subjects whohave been diagnosed with Alzheimer's disease or who are suspected by aphysician of having Alzheimer's disease. However, these methods are alsoof particular use when the subject in need thereof has any othercondition associated with cognitive impairment, for example, a conditionin which the impairment is accompanied with an increase in beta amyloid,a decrease in the rate of beta amyloid clearance, and/or an increase inamyloid plaque deposition.

Cognitive function and cognitive impairment may be readily evaluatedusing tests well known in the art. Performance in these tests can becompared over time to determine whether a treated subject is improvingor whether further decline has stopped or slowed, relative to theprevious rate of decline of that patient or compared to an average rateof decline. Exemplary tests used in animal studies are provided in, forexample, Animal Models of Cognitive Impairment, Levin E D, Buccafusco JJ, editors. Boca Raton (Fla.): CRC Press; 2006. Tests of cognitivefunction, including memory and learning for evaluating human patientsare well known in the art and regularly used to evaluate and monitorsubjects having or suspected of having cognitive disorders such as AD.Even in healthy individuals, these and other standard tests of cognitivefunction can be readily used to evaluate beneficial affects over time.

Compounds, salts and prodrugs of the disclosure (P₂Y₆receptor-modulating compounds, salts and/or prodrugs thereof) are alsouseful in the treatment of Parkinson's disease. For example, compounds,salts and prodrugs of the disclosure can be used to improve the motorimpairments symptomatic of Parkinson's disease. Moreover, compounds,salts and prodrugs of the disclosure are useful for treating the memoryimpairment symptomatic of Parkinson's disease. Without being bound bytheory, impairment of microglial phagocytosis is thought to be amechanism of action underlying accumulation of alpha synuclein and theformation of Lewy bodies (and resulting neurodegeneration) inParkinson's disease. Compounds, salts and prodrugs of the disclosure maybe used to increase clearance or otherwise decrease extracellularalpha-synuclein, to decrease intracellular accumulation ofalpha-synuclein, and/or to decrease or prevent the formation of Lewybodies in a subject in need thereof. In certain embodiments, compounds,salts and prodrugs of the disclosure enhance phagocytosis, such asmicroglial phagocytosis.

Compounds of the disclosure, including salts and prodrugs, may be testedin animal models of Parkinson's disease. Exemplary models include micethat over express α-synuclein, express human mutant forms ofα-synuclein, mice that express LRKK2 mutations, as well as mice treatedwith MTTP. Additional information regarding these animal models isreadily available from Jackson Laboratories (see also the websiteresearch.jax.org/grs/parkinsons.html), as well as in numerouspublications disclosing the use of these validated models.

2. Down Syndrome

Compounds, salts and/or prodrugs thereof, of the present disclosure mayalso be useful to prevent, treat, and alleviate symptoms of DownSyndrome (DS). Down Syndrome (DS) is a genetic condition characterizedby trisomy of chromosome 21. DS is named after Dr. John Langdon Down, anEnglish physician who first described the characteristics of DS in 1866.It was not until 1959 that Jerome Leieune and Patricia Jacobsindependently first determined the cause to be trisomy of the 21stchromosome.

In recent years, it has become evident that there is relationshipbetween Alzheimer's Disease (AD) and DS. Specifically, the production ofexcessive beta amyloid plaques and amyloid angiopathy occurs in both DSand Alzheimer's Disease (AD) (Delabar et al. (1987) “Beta amyloid genetriplication in Alzheimer's disease and karyotypically normal DownSyndrome. Science 235: 1390-1392). Without being bound by theory, giventhat both AD and Down Syndrome are characterized by both beta amyloidplaques and cognitive impairment, methods and compositions that decreaseplaque burden and/or enhance beta amyloid clearance are useful fortreating AD and Down Syndrome (e.g., providing a beneficial effectand/or decreasing one or more symptoms of AD or Down Syndrome).Exemplary beneficial effects include, but are not limited to, improvingcognitive function, decreasing cognitive impairment, decreasing plaqueburden, enhancing beta amyloid clearance, improving memory, and thelike.

3. Pain

In certain aspects, the compounds, salts and/or prodrugs thereof, asdescribed herein (P₂Y₆ receptor-modulating compounds, salts and/orprodrugs of the disclosure) can be used to treat patients having pain.Pain is a complex physiological process that involves a number ofsensory and neural mechanisms. Compounds, salts and/or prodrugs thereof,to be used according to the present disclosure are suitable foradministration to a subject for treatment (including prevention and/oralleviation) of chronic and/or acute pain, in particularnon-inflammatory musculoskeletal pain such as back pain, fibromyalgiaand myofascial pain, more particularly for reduction of the associatedmuscular hyperalgesia or muscular allodynia. Nonlimiting examples oftypes of pain that can be treated by the compounds, salts and/orprodrugs thereof, compositions and methods of the present disclosureinclude chronic conditions such as musculoskeletal pain, includingfibromyalgia, myofascial pain, back pain, pain during menstruation, painduring osteoarthritis, pain during rheumatoid arthritis, pain duringgastrointestinal inflammation, pain during inflammation of the heartmuscle, pain during multiple sclerosis, pain during neuritis, painduring AIDS, pain during chemotherapy, tumor pain, headache, CPS(chronic pain syndrome), central pain, neuropathic pain such astrigeminal neuralgia, shingles, stamp pain, phantom limb pain,temporomandibular joint disorder, nerve injury, migraine, post-herpeticneuralgia, neuropathic pain encountered as a consequence of injuries,amputation infections, metabolic disorders or degenerative diseases ofthe nervous system, neuropathic pain associated with diabetes,pseudesthesia, hypothyroidism, uremia, vitamin deficiency or alcoholism;and acute pain such as pain after injuries, postoperative pain, painduring acute gout or pain during operations, such as jaw surgery.

Acute pain is typically a physiological signal indicating a potential oractual injury. Chronic pain can be somatogenic (organic) or psychogenic.Chronic pain is frequently accompanied or followed by vegetative signs,such as, for example, lassitude or sleep disturbance. Acute pain may betreated with compounds, salts and/or prodrugs thereof, as describedherein.

Somatogenic pain may be of nociceptive, inflammatory or neuropathicorigin. Nociceptive pain is related to activation of somatic or visceralpain-sensitive nerve fibers, typically by physical or chemical injury totissues. Inflammatory pain results from inflammation, for example aninflammatory response of living tissues to any stimulus includinginjury, infection or irritation. Neuropathic pain results fromdysfunction in the nervous system. Neuropathic pain is believed to besustained by aberrant somatosensory mechanisms in the peripheral nervoussystem, the central nervous system (CNS), or both. According to oneaspect of the disclosure, somatogenic pain may be treated by compounds,salts and/or prodrugs thereof, as described herein.

Non-inflammatory musculoskeletal pain is a particular form of chronicpain that is generally not traced to a specific structural orinflammatory cause and that generally does not appear to be induced bytissue damage and macrophage infiltration (resulting in edema) as occursin a classical immune system response. Although non-inflammatorymusculoskeletal pain is believed to result from peripheral and/orcentral sensitization, the cause is not presently fully understood. Itis often associated with physical or mental stress, lack of adequate orrestful sleep, or exposure to cold or damp. Non-inflammatorymusculoskeletal pain is also believed to be associated with orprecipitated by systemic disorders such as viral or other infections.Examples of non-inflammatory musculoskeletal pain include neck andshoulder pain and spasms, low back pain, and achy chest or thighmuscles, which may be treated by a compound, or salt and/or prodrugthereof, of the present disclosure. Non-inflammatory musculoskeletalpain may be generalized or localized.

According to a further aspect of the disclosure, a compound, or saltand/or prodrug thereof, as described herein may be administered to asubject to treat fibromyalgia syndrome (FMS) and myofascial painsyndrome (MPS). FMS and MPS are medical conditions characterized byfibromyalgia and myofascial pain respectively, which are two types ofnon-inflammatory musculoskeletal pain. FMS is a complex syndromeassociated with significant impairment of quality of life and can resultin substantial financial costs. Fibromyalgia is a systemic process thattypically causes tender points (local tender areas in normal-appearingtissues) in particular areas of the body and is frequently associatedwith a poor sleep pattern and/or stressful environment. Diagnosis offibromyalgia is typically based on a history of widespread pain (e.g.,bilateral, upper and lower body, and/or spinal pain), and presence ofexcessive tenderness on applying pressure to a number of (sometimes moreprecisely defined as at least 11 out of 18) specific muscle-tendersites. FMS is typically a chronic syndrome that causes pain andstiffness throughout the tissues that support and move the bones andjoints. Myofascial pain syndrome (MPS) is a chronic non-degenerative,non-inflammatory musculoskeletal condition often associated with spasmor pain in the masticatory muscles. Distinct areas within muscles ortheir delicate connective tissue coverings (fascia) become abnormallythickened or tight. When the myofascial tissues tighten and lose theirelasticity, the ability of neurotransmitters to send and receivemessages between the brain and body is disrupted. Specific discreteareas of muscle may be tender when firm fingertip pressure is applied;these areas are called tender or trigger points. Symptoms of MPS includemuscle stiffness and aching and sharp shooting pains or tingling andnumbness in areas distant from a trigger point. The discomfort may causesleep disturbance, fatigue and depression. Most commonly trigger pointsare in the jaw (temporomandibular) region, neck, back or buttocks.Myofascial pain differs from fibromyalgia: MPS and FMS are two separateentities, each having its own pathology, but sharing the muscle as acommon pathway of pain. Myofascial pain is typically a more localized orregional (along the muscle and surrounding fascia tissues) pain processthat is often associated with trigger point tenderness. Myofascial paincan be treated by a variety of methods (sometimes in combination)including stretching, ultrasound, ice sprays with stretching, exercises,and injections of anesthetic.

A further non-inflammatory musculoskeletal pain condition is back pain,notably low back pain, which may also be treated with a compound, orsalt and/or prodrug thereof, of the present disclosure. This conditionmay also be treating by administering a compound, or salt and/or prodrugthereof, of the present disclosure to a subject in need thereof. Backpain is a common musculoskeletal symptom that may be either acute orchronic. It may be caused by a variety of diseases and disorders thataffect the lumbar spine. Low back pain is often accompanied by sciatica,which is pain that involves the sciatic nerve and is felt in the lowerback, the buttocks, and the backs of the thighs.

4. Glaucoma and Intraocular Pressure

In another aspect, the disclosure provides for methods of treatingglaucoma in a subject in need thereof. Compounds of the disclosure, suchas any of the compounds, salts and/or prodrugs described herein, may beused to treat glaucoma. For example, P₂Y₆ receptor-modulating compounds,salts and/or prodrugs thereof may be used to decrease intraocularpressure (IOP), such as the elevated intraocular pressure observed inmost cases of glaucoma. Also provided are methods for treating ocularhypertension in a subject in need thereof. Without being bound bytheory, P₂Y₆ receptor agonists of the disclosure may be used to reduceIOP, thereby treating ocular hypertension. For any of the foregoing, thedisclosure contemplates administering an effective amount of a P₂Y₆receptor agonist, such as any of the agonists described herein, to asubject in need thereof to decrease intraocular pressure, such aselevated intraocular pressure, and/or to treat glaucoma (e.g., improve,or stop or slow the progression of one or more symptoms of thecondition).

Glaucoma refers to a group of eye conditions that lead to damage to theoptic nerve. This nerve carries visual information from the eye to thebrain. In most cases, damage to the optic nerve is due to increasedpressure in the eye, also known as intraocular pressure (IOP). Overtime, the elevated intraocular pressure and optic nerve damage leads tovisual field loss, and may result in blindness. Ocular hypertension isintraocular pressure higher than normal in the absence of optic nervedamage or visual field loss. Currently, ophthalmologists generallydefine normal intraocular pressure as from 10 mmHg and 21 mmHg, andintraocular pressure above 21 mmHg is considered ocular hypertension orelevated intraocular pressure. Ocular hypertension is considered asignificant risk factor for developing glaucoma, and thus, patients withocular hypertension should be closely monitored for glaucoma.

Glaucoma is the second-most common cause of blindness in the UnitedStates. The nerve damage involves loss of retinal ganglion cells in acharacteristic pattern. The many different subtypes of glaucoma can allbe considered to be a type of optic neuropathy. Raised intraocularpressure (above 21 mmHg or 2.8 kPa) is the most important and onlymodifiable risk factor for glaucoma. However, some patients may havehigh eye pressure for years and never develop damage, while others candevelop nerve damage at a relatively low pressure. Untreated glaucomacan lead to permanent damage of the optic nerve and resultant visualfield loss, which over time can progress to blindness.

The two main types of glaucoma, each of which are marked by elevatedintraocular pressure, are open-angle and angle-closure. Open-angle andangle-closure glaucoma also include the following variants: (i)secondary glaucoma; (ii) pigmentary glaucoma; (iii) pseudoexfoliativeglaucoma; (iv) traumatic glaucoma; (v) neovascular glaucoma; and (vi)irido corneal endothelial syndrome (ICE).

Open-angle glaucoma, the most common form of glaucoma, accounts for atleast 90% of all glaucoma cases. Open-angle glaucoma is also calledprimary or chronic glaucoma and generally has the followingcharacteristics: (i) caused by the slow clogging of the drainage canals,resulting in increased eye pressure; (ii) has a wide and open anglebetween the iris and cornea; and (iii) develops slowly and is a lifelongcondition. Angle-closure glaucoma, a less common form of glaucoma, isalso called acute glaucoma or narrow-angle glaucoma. Unlike open-angleglaucoma, angle-closure glaucoma is a result of the angle between theiris and cornea closing, and angle-closure glaucoma generally has thefollowing characteristics: (i) caused by blocked drainage canals,resulting in a sudden rise in intraocular pressure; (ii) has a closed ornarrow angle between the iris and cornea; (iii) develops very quickly;and (iv) demands immediate medical attention.

The disclosure contemplates methods of treating open-angle and/orangle-closure glaucoma, including methods of treating variants ofopen-angle and/or angle-closure glaucoma. In certain embodiments,administration of a compound, salt, or prodrug of the disclosure to apatient having open-angle and/or angle-closure glaucoma decreasesintraocular pressure, thereby treating the glaucoma in the patient. Incertain embodiments, reducing intraocular pressure slows or stopsfurther damage to the optic nerve (e.g., prevents occurrence of furtherdamage to the optic nerve). In certain embodiments, reducing intraocularpressure slows or stops further loss of or damage to vision or thevisual field. Moreover, the disclosure contemplates methods of treatingoptic neuropathy in a patient in need thereof by administering aneffective amount of a compound, salt and/or prodrug of the disclosure.

In addition to open-angle and angle-closure glaucoma, an additional raretype of glaucoma is congenital glaucoma. In certain embodiments, thedisclosure contemplates methods of treating congenital glaucoma in asubject in need thereof. This type of glaucoma occurs in babies whenthere is incorrect or incomplete development of the eye's drainagecanals during the prenatal period.

A fourth type of glaucoma is referred to as secondary glaucoma.Secondary glaucoma occurs as a consequence of trauma, systemic disease,or as a side-effect of certain drugs (e.g., corticosteroids). In certainembodiments, the disclosure contemplates methods of treating secondaryglaucoma in a subject in need thereof. Systemic diseases that may leadto or exacerbate glaucoma include hypertension and diabetes.

Additionally, although most glaucoma is characterized by elevatedintraocular pressure which leads to damage of the optic nerve, there arecases of glaucoma referred to as low-tension or normal-pressureglaucoma. In these cases, the optic nerve is damaged despite the factthat eye pressure is not very high. In certain embodiments, thedisclosure contemplates methods of treating low-tension or normalpressure glaucoma. In certain embodiments, glaucoma treated using themethods of the disclosure is characterized by elevated intraocularpressure and/or ocular hypertension (e.g., the glaucoma is notlow-tension or normal pressure glaucoma).

In addition to elevated intraocular pressure, which results in damage tothe optic nerve, the various types of glaucoma are characterized byparticular symptoms. The disclosure contemplates that administration ofP₂Y₆ receptor-modulating compounds, salts and/or prodrugs of thedisclosure may be used to alleviate one or more symptoms of glaucoma,including to alleviate one or more symptoms of any of the particulartypes of glaucoma described herein.

In open-angle glaucoma, there are actually few overt symptoms. Patientshave elevated intraocular pressure or, at least, periods of elevatedintraocular pressure. However, the intraocular pressure slowly damagesthe optic nerve, and thus, vision loss is slow and not typicallyaccompanied by pain. In fact, noticeable vision loss, which typicallymanifests as slow loss of peripheral vision leading to tunnel vision, isa symptom of relatively advanced and severe disease. Ultimately,open-angle glaucoma can lead to blindness.

In angle-closure glaucoma, patients do experience one or more of thefollowing symptoms, and these symptoms may come and go or steadilybecome worse. Exemplary symptoms include sudden, severe pain (typicallyin only one eye), decreased or cloudy vision (also known as “steamy”vision), nausea, vomiting, rainbow-like halos around lights, red eye,and the sensation that the eye is swollen.

In congenital glaucoma, the symptoms are usually noticed when the childis a few months old. Exemplary symptoms include one or more of thefollowing: cloudiness of the front of the eye, enlargement of one orboth eyes, red eye, sensitivity to light, and excessive tearing.

There are currently several tests that are used to measure intraocularpressure, to detect elevated intraocular pressure and to diagnoseglaucoma. In certain embodiments, one or more of these tests are used todiagnose glaucoma and/or intraocular hypertension prior to initiation oftreatment with a compound, salt and/or prodrug of the disclosure.Exemplary tests that can be used, alone or in combination, includetonometry, gonioscopy, optic nerve imaging, slit lamp examination,examination of the retina, visual acuity measurements, and visual fieldmeasurements. These tests can also be used to monitor a patient afterinitiation of treatment. For example, these tests can be used todetermine whether treatment has slowed or stopped the progress of thedisease, has decreased elevated intraocular pressure (e.g., restorednormal intraocular pressure), and whether the patient's vision hasimproved or ceased further deterioration.

In addition, the disclosure provides methods of decreasing elevatedintraocular pressure in a subject in need thereof. Suitable subjectsinclude, as discussed in detail above, subjects having glaucoma (any ofthe forms of glaucoma described herein) or subjects with ocularhypertension. Decreasing intraocular pressure, such as elevatedintraocular pressure, in these subjects (e.g., such as by administeringan effective amount of a compound, salt and/or prodrug of thedisclosure), such as human patients, helps ameliorate one or moresymptoms of the condition, helps slow or stop damage to the optic nerveand to vision, and may even permit improvement in the patient'scondition—particularly in cases where significant damage has not yetoccurred. Given that elevated intraocular pressure in ocularhypertension is a major risk factor for developing glaucoma, decreasingelevated IOP in such patients may help decrease the patient's risk ofdeveloping glaucoma.

Compounds of the disclosure, including salts and prodrugs, may be testedin animal models of glaucoma and ocular hypertension. Exemplary modelsare known in the art and, for example, described in Bouhenni et al.,Journal of Biomedicine and Biotechnology, Volumne 2012, Article ID692609, 11 pages, doi: 10.1155/2012/692609.

Agonists of the disclosure may be administered using any suitable routeof administration described herein, including oral, intravenous, orlocal administration to the eye (e.g., eye drops, injection into theeye, or implantation of a drug eluting device).

In other embodiments, the disclosure provides methods of decreasingintraocular pressure (e.g., decreasing elevated intraocular pressure) ina subject in need thereof, wherein the subject in need thereof has acondition other than or in addition to glaucoma. Exemplary conditionscaused or exacerbated by elevated IOP which may be treated include:Reese-Ellsworth syndrome, hydrophthalmos, and ophthalmic zoster.

5. Inflammatory Conditions

In another aspect, the compounds, salts and/or prodrugs thereof, andcompositions as described herein can be used to treat patients sufferingfrom P₂Y₆ receptor-related conditions or conditions that can beameliorated by modulating, for example, agonizing, P₂Y₆ receptoractivity, such as an inflammatory condition. Accordingly, the disclosureprovides methods of treating an inflammatory condition in a subject inneed thereof. Compounds, salts, and prodrugs of the disclosure, such asany of the compounds, salts or prodrugs described herein (e.g., P₂Y₆receptor-modulating compounds, salts and/or prodrugs of the disclosure),may be used to treat an inflammatory condition.

As used herein, an inflammatory condition is a disease or conditioncharacterized, in whole or in part, by inflammation or an inflammatoryresponse in the patient. Typically, one or more of the symptoms of theinflammatory disease or condition is caused or exacerbated by aninappropriate, misregulated, or overactive inflammatory response.Inflammatory diseases or conditions may be chronic or acute. In certainembodiments, the inflammatory disease or condition is an autoimmunedisorder. In certain embodiments, compounds, salts, and prodrugs of thedisclosure are used to decrease inflammation, to decrease expression ofone or more inflammatory cytokines, and/or to decrease an overactiveinflammatory response in a subject having an inflammatory condition.Thus, the disclosure provides a method of decreasing inflammation, amethod of decreasing expression of one or more inflammatory cytokines,and/or a method of decreasing an overactive inflammatory response in asubject in need thereof.

Inflammatory conditions treatable using the compounds, salts, andprodrugs of the disclosure may be characterized, for example, based onthe primary tissue affected, the mechanism of action underlying thecondition, or the portion of the immune system that is misregulated oroveractive. Examples of inflammatory conditions, as well categories ofdiseases and conditions are provided herein. The disclosure contemplatesmethods of treating (e.g., such as by decreasing inflammation,decreasing expression of one or more inflammatory cytokines, and/ordecreasing an overactive inflammatory response) inflammatory conditions,generally, as well as methods of treating any of the categories ofconditions or any of the specific conditions described herein.

In certain embodiments, examples of inflammatory conditions that may betreated include inflammation of the lungs, joints, connective tissue,eyes, nose, bowel, kidney, liver, skin, central nervous system, vascularsystem, heart, or adipose tissue. In certain embodiments, inflammatoryconditions which may be treated include inflammation due to theinfiltration of leukocytes or other immune effector cells into affectedtissue. In certain embodiments, inflammatory conditions which may betreated include inflammation mediated by IgE antibodies. Other relevantexamples of inflammatory conditions which may be treated by the presentdisclosure include inflammation caused by infectious agents, includingbut not limited to viruses, bacteria, fungi, and parasites. In certainembodiments, the inflammatory condition that is treated is an allergicreaction. In certain embodiments, the inflammatory condition is anautoimmune disease. The disclosure contemplates that some inflammatoryconditions involve inflammation in multiple tissues. Moreover, thedisclosure contemplates that some inflammatory conditions may fall intomultiple categories. For example, a condition may be described andcategorized as an autoimmune condition and/or it may also be describedand categorized based on the primary tissue(s) affected (e.g., aninflammatory skin or joint condition). In certain embodiments, aninflammatory condition treatable accordinging to the methods describedherein falls into more than one category of condition.

Inflammatory lung conditions include asthma, adult respiratory distresssyndrome, bronchitis, pulmonary inflammation, pulmonary fibrosis, andcystic fibrosis (which may additionally or alternatively involve thegastro-intestinal tract or other tissue(s)). In certain embodiments, thedisclosure provides methods of treating an inflammatory lung conditionin a patient in need thereof (e.g., a patient having an inflammatorylung condition) by administering an effective amount a compound, salt,or prodrug of the disclosure. In certain embodiments, treating aninflammatory lung condition comprises decreasing inflammation in thelung in the patient, decreasing misregulation of inflammatory cytokinesin the patient, and/or decreasing one or more symptoms of theinflammatory lung condition in the subject. By way of example, symptomsof the inflammatory lung condition that may be improved, locally orsystemically, by decreasing inflammation or the inflammatory responseinclude, but are not limited to: oxygen saturation (patients haveimproved oxygen saturation following treatment), ease of breathing(patients experience greater ease when breathing and a decrease inlabored breather), reliance on external oxygen (patient reliance onexternal oxygen supplementation is decreased), and reliance on inhalersor nebulizers (patient reliance on other drugs is decreased).Improvement in a patient (e.g., decrease in symptoms) may be measureddirectly by assessing inflammation or scarring in the lung or byevaluating cytokine expression in lung fluids. Improvement can also beassessed by evaluating improvement in patient activity levels, walkingdistance and speed, and decreased reliance on oxygen supplementation.

Inflammatory joint conditions include rheumatoid arthritis, rheumatoidspondylitis, juvenile rheumatoid arthritis, osteoarthritis, goutyarthritis and other arthritic conditions. In certain embodiments, theinflammatory joint condition is rheumatoid arthritis or psoriaticarthritis. In certain embodiments, the disclosure provides methods oftreating an inflammatory joint condition in a patient in need thereof,such as treating any of the foregoing conditions, by administering aneffective amount of a compound, salt and/or prodrug of the disclosure.In certain embodiments, treating an inflammatory joint conditioncomprises decreasing inflammation in the joints in the patient,decreasing misregulation of inflammatory cytokines in the patient,decreasing circulating levels of one or more cytokines in plasma of thepatient, and/or decreasing one or more symptoms of the inflammatoryjoint condition in the subject. By way of example, symptoms of theinflammatory joint condition that may be improved by decreasinginflammation or the inflammatory response, locally and/or systemically,include, but are not limited to: swelling in one or more joints,tenderness and/or pain in one or more joints, decreased mobility and/oruse of one or more joints, impaired ability to perform daily tasks(e.g., ability to perform daily tasks including self care tasks isimproved), and reliance on walking assistance (patient reliance on awalker, cane, or wheel chair is decreased). Improvement in patients(e.g., decrease in symptoms) may be measured directly by assessinginflammation in the joints or by evaluating cytokine expression in jointfluid. Improvement can also be assessed by evaluating improvement inpatient activity levels and quality of life measures, walking distanceand speed, range of motion, mobility, and decreased reliance on mobilityaids. In certain embodiments, the inflammatory joint condition is alsoan autoimmune condition, and the disclosure contemplates treating suchcondition.

Inflammatory eye conditions include uveitis (including iritis),conjunctivitis, scleritis, and keratoconjunctivitis sicca. In certainembodiments, the disclosure contemplates treating an inflammatory eyecondition in a patient in need thereof, including by administering acompound, salt and/or prodrug of the disclosure systemically or locallyto the eye, such as via eye drops.

Inflammatory bowel conditions include Crohn's disease, ulcerativecolitis, inflammatory bowel disease, inflammatory bowel syndrome, anddistal proctitis. In certain embodiments, the disclosure providesmethods of treating an inflammatory bowel condition in a patient in needthereof by administering an effective amount a compound, salt and/orprodrug of the disclosure. In certain embodiments, treating aninflammatory bowel condition comprises decreasing inflammation in thegastro-intestinal tract in the patient, decreasing misregulation ofinflammatory cytokines in the patient, decreasing the circulating levelsof one or more cytokines in plasma of the patient, and/or decreasing oneor more symptoms of the inflammatory bowel condition in the subject. Byway of example, symptoms of the inflammatory bowel condition that may beimproved by decreasing inflammation or the inflammatory response,locally and/or systemically, include, but are not limited to: diarrhea,constipation, blotting, pain, flatulence, blood in stool, weight loss(treating stabilizes weight and/or prevents further weight loss;treatment helps promote improved nutrition and weight gain, whereneeded), malabsorption, and malnutrition. Improvement in patients (e.g.,decrease in symptoms) may be measured directly by assessing inflammationin the gastrointestinal tract or by evaluating cytokine expression orlevels of cytokines in plasma in patients. Improvement can also beassessed by evaluating improvement in any of the foregoing symptoms,evaluating patient self-reporting of quality of life and symptomreduction, evaluating patient weight and nutrition status. In certainembodiments, the inflammatory bowel condition being treated is also anautoimmune condition, such as ulcerative colitis.

Inflammatory skin conditions include conditions associated with cellproliferation, such as psoriasis, eczema, and dermatitis (e. g.,eczematous dermatitides, topic and seborrheic dermatitis, allergic orirritant contact dermatitis, eczema craquelee, photoallergic dermatitis,phototoxicdermatitis, phytophotodermatitis, radiation dermatitis, andstasis dermatitis). Other inflammatory skin conditions include, but arenot limited to, ulcers and erosions resulting from trauma, burns,bullous disorders, or ischemia of the skin or mucous membranes, severalforms of ichthyoses, epidermolysis bullosae, hypertrophic scars,keloids, cutaneous changes of intrinsic aging, photo aging, frictionalblistering caused by mechanical shearing of the skin and cutaneousatrophy resulting from the topical use of corticosteroids. Additionalinflammatory skin conditions include inflammation of mucous membranes,such as cheilitis, nasal irritation, mucositis and vulvovaginitis. Otherinflammatory skin conditions include acne, rosacea, boils, carbuncles,pemphigus, cellulitis, Grover's disease, hidradenitis suppurativa, andlichen planus. In certain embodiments, the disclosure provides methodsof treating an inflammatory skin condition in a patient in need thereofby administering an effective amount a compound, salt and/or prodrug ofthe disclosure. In certain embodiments, treating an inflammatory skincondition comprises decreasing skin inflammation in the patient,decreasing misregulation of inflammatory cytokines in the patient,decreasing the circulating levels of one or more cytokines in plasma ofthe patient, and/or decreasing one or more symptoms of the inflammatoryskin condition in the subject. By way of example, symptoms of theinflammatory skin condition that may be improved by decreasinginflammation or the inflammatory response, locally and/or systemically,include, but are not limited to: skin swelling, redness, itching,flaking, blistering, bleeding, sensitivity to touch, and sensitivity tolight or sun. Improvement in patients (e.g., decrease in symptoms) maybe measured directly by assessing inflammation or by evaluating cytokineexpression in patients. Improvement can also be assessed by evaluatingimprovement in any of the foregoing symptoms, or by evaluating patientself-reporting of quality of life and symptom reduction. In certainembodiments, the inflammatory skin condition is also an autoimmunecondition, such as psoriasis. The disclosure provides methods oftreating an inflammatory skin condition.

Inflammatory conditions of the endocrine system include, but are notlimited to, autoimmune thyroiditis (Hashimoto's disease), Type Idiabetes, inflammation in liver and adipose tissue associated with TypeII diabetes, and acute and chronic inflammation of the adrenal cortex.Inflammatory conditions of the cardiovascular system include, but arenot limited to, coronary infarct damage, peripheral vascular disease,myocarditis, vasculitis, revascularization of stenosis, atherosclerosis,and vascular disease associated with Type II diabetes. In certainembodiments, the disclosure provides methods of treating an inflammatoryendocrine condition or cardiovascular condition in a patient in needthereof by administering an effective amount a compound, salt and/orprodrug of the disclosure. In certain embodiments, treating aninflammatory endocrine condition or cardiovascular condition comprisesdecreasing inflammation in the patient, decreasing misregulation ofinflammatory cytokines in the patient, decreasing circulating levels ofone or more cytokines in plasma of the patient, and/or decreasing one ormore symptoms of the inflammatory endocrine condition or theinflammatory cardiovascular condition in the subject. As noted above,endocrine disorders impact a diverse array of organs, and thus, thesymptoms of the disorders vary depending on the tissue affected. By wayof example, symptoms of the inflammatory cardiovascular condition thatmay be improved by decreasing inflammation or the inflammatory response,locally and/or systemically, include, but are not limited to: chestpain, irregular heart rhythm, angina, shortness of breath, dizziness,decreased activity level, and fatigue. Improvement in patients (e.g.,decrease in symptoms) may be measured directly by assessing inflammationor by evaluating cytokine expression in patients. Improvement can alsobe assessed by evaluating improvement in any of the foregoing symptoms,evaluating patient self-reporting of quality of life and symptomreduction, and evaluating improvement in activity levels.

Inflammatory conditions of the kidney include, but are not limited to,glomerulonephritis, interstitial nephritis, lupus nephritis, nephritissecondary to Wegener's disease, acute renal failure secondary to acutenephritis, Goodpasture's syndrome, post-obstructive syndrome and tubularischemia. In certain embodiments, the disclosure provides methods oftreating an inflammatory kidney condition in a patient in need thereofby administering an effective amount a compound of the disclosure. Incertain embodiments, treating an inflammatory kidney condition comprisesdecreasing inflammation in the kidney in the patient, decreasingmisregulation of inflammatory cytokines in the patient, decreasingcirculating levels of one or more cytokines in plasma of the patient,and/or decreasing one or more symptoms of the inflammatory kidneycondition in the subject. By way of example, symptoms of theinflammatory kidney condition that may be improved by decreasinginflammation or the inflammatory response, locally and/or systemically,include, but are not limited to: increased or decreased frequency ofurination, difficulty urinating, abnormal levels of protein in urine,misregulation of salt levels, blood in urine, kidney failure, andreliance on dialysis (treatment is used to decrease or eliminatereliance on dialysis). Improvement in patients (e.g., decrease insymptoms) may be measured directly by assessing inflammation or byevaluating cytokine expression in patients. Improvement can also beassessed by evaluating improvement in any of the foregoing symptoms,evaluating patient self-reporting of quality of life and symptomreduction, or evaluating decreased reliance on dialysis (or increasingthe period of time between diagnosis and onset of the time when thepatient requires dialysis). Improvement can also be assessed by anincrease in the period of time between diagnosis and progressing to endstage renal disease (ESRD) and/or delay or elimination of the need for akidney transplant. In certain embodiments, the inflammatory condition ofthe kidney is an autoimmune condition, and the disclosure provides formethods of treating such a condition.

Inflammatory conditions of the liver include, but are not limited to,hepatitis (arising from viral infection, autoimmune responses, drugtreatments, toxins, environmental agents, or as a secondary consequenceof a primary disorder), obesity, biliary atresia, primary biliarycirrhosis and primary sclerosing cholangitis. Inflammatory diseases ofthe adipose tissues include, but are not limited to, obesity. In certainembodiments, the disclosure provides methods of treating an inflammatoryliver condition in a patient in need thereof by administering aneffective amount a compound of the disclosure. In certain embodiments,treating an inflammatory liver condition comprises decreasinginflammation in the liver in the patient, decreasing misregulation ofinflammatory cytokines in the patient, decreasing circulating levels ofone or more cytokines in plasma of the patient, and/or decreasing one ormore symptoms of the inflammatory liver condition in the subject. By wayof example, symptoms of the inflammatory liver condition that may beimproved by decreasing inflammation or the inflammatory response,locally and/or systemically, include, but are not limited to: jaundice,abdominal swelling, dark urine, pale stool, bloody stool, fatigue,nausea, and loss of appetite. Improvement in patients (e.g., decrease insymptoms) may be measured directly by assessing inflammation or byevaluating cytokine expression in patients. Improvement can also beassessed by evaluating improvement in any of the foregoing symptoms,evaluating patient self-reporting of quality of life and symptomreduction. Improvement can also be assessed by a delay or elimination ofthe need for a liver transplant.

Inflammatory conditions of the central nervous system include, but arenot limited to, multiple sclerosis and neurodegenerative diseases suchas Alzheimer's disease, Parkinson's disease or dementia associated withHIV infection. In certain embodiments, the disclosure provides methodsof treating an inflammatory condition in a subject in need thereof, withthe proviso that the subject does not have and/or is not being treatedfor Alzheimer's disease or Parkinson's disease. In certain embodiments,the disclosure provides methods of treating an inflammatory condition ina subject in need thereof, with the proviso that the subject does nothave and/or is not being treated for an inflammatory condition of thecentral nervous system and/or a neuronal or neurodegenerative conditioncharacterized by an inflammatory component. In certain embodiments, theinflammatory condition to be treated by the methods of the disclosure isnot an inflammatory condition of the central nervous system. In certainembodiments, the inflammatory condition to be treated by the methods ofthe disclosure is not an inflammatory condition of the peripheralnervous system.

In certain embodiments, the inflammatory condition is an autoimmunedisease. Exemplary autoimmune diseases include, but are not limited to,rheumatoid arthritis, psoriasis (including plaque psoriasis), psoriaticarthritis, ankylosing spondylitis, ulcerative colitis, multiplesclerosis, lupus, alopecia, autoimmune pancreatitis, Celiac disease,Behcet's disease, Cushing syndrome, and Grave's disease. In certainembodiments, the disclosure provides methods of treating an autoimmunedisease in a patient in need thereof by administering an effectiveamount a compound, salt and/or prodrug of the disclosure.

In certain embodiments, the inflammatory condition is a rheumatoiddisorder. Exemplary rheumatoid disorders include, but are not limitedto, rheumatoid arthritis, juvenile arthritis, bursitis, spondylitis,gout, scleroderma, Still's disease, and vasculitis. We note that certaincategories of conditions overlap. For example, rheumatoid arthritis isan inflammatory rheumatoid disorder, an inflammatory joint disorder, andan autoimmune disorder. In certain embodiments, the disclosure providesmethods of treating a rheumatoid disorder in a patient in need thereofby administering an effective amount a compound, salt or prodrug of thedisclosure.

Other inflammatory conditions include periodontal disease, tissuenecrosis in chronic inflammation, endotoxin shock, smooth muscleproliferation disorders, tissue damage following ischemia reperfusioninjury, and tissue rejection following transplant surgery.

In certain embodiments, the compounds and/or compositions of thedisclosure are not for use in the treatment of Alzheimer's disease orParkinson's disease. In certain embodiments, the compounds and/orcompositions of the disclosure are not for use in the treatment of apatient who has been diagnosed with or is suspected of havingAlzheimer's disease or Parkinson's disease. In certain embodiments, thecompounds and/or compositions of the disclosure are not for use in thetreatment of a neural or neurodegenerative disease or disorder. Incertain embodiments, the compounds and/or compositions of the disclosureare not for use in the treatment of inflammatory pain. In certainembodiments, the compounds and/or compositions of the disclosure are notfor use in the treatment of pain. In certain embodiments of any of theforegoing, the term “are not for use in the treatment of” means that acompound is not being used to treat the condition and/or is not beingused with the purpose of treating the condition. In other words, incertain embodiments, the inflammatory condition being treated is notAlzheimer's disease or is not Parkinson's disease, or is not aneurodegenerative disease (in other words, is a non-neurodegenerative,inflammatory condition). Similarly, in certain embodiments, the subjectin need of treatment for an inflammatory condition, including any of theinflammatory disorders set forth herein, is not a subject diagnosed withor suspected of having Alzheimer's disease and/or Parkinson's disease.In certain embodiments, the subject in need of treatment for aninflammatory condition, including any of the inflammatory disorders setforth herein, is not a subject being treated for a neurologicalcondition or a neurodegenerative condition.

The present disclosure further provides a method of treating orpreventing inflammation associated with post-surgical wound healing in apatient.

It should be noted that the inflammatory conditions and categories ofconditions cited above are meant to be exemplary rather than exhaustive.Those skilled in the art would recognize that additional inflammatorydiseases (e.g., systemic or local immune imbalance or dysfunction due toan injury, infection, insult, inherited disorder, or an environmentalintoxicant or perturbant to the subject's physiology) may be treated bythe methods of the current disclosure.

Inflammatory conditions can be categorized by the primary tissueaffected. Illustrative examples of inflammatory conditions socategorized are provided above. The disclosure contemplates treating anysuch categories of inflammatory conditions by administering an effectiveamount of a compound, salt and/or prodrug of the disclosure to a patientin need thereof. Moreover, inflammatory conditions can be furthercategorized based on the mechanism of action underlying the condition.For example, inflammatory conditions may be categorized as autoimmune,as chronic versus acute, based on the portion of the immune system thatis hyperactivated or upregulated in the condition, or based on thecytokines or category of cytokines misregulated in the condition. Incertain embodiments, the inflammatory condition is an allergic reactionor other inflammatory response mediated by IgE antibodies. In certainembodiments, the inflammatory condition is mediated by misregulation ofinflammatory cytokines, such as interleukins (ILs) or tumor necrosisfactor alpha (TNF).

Inflammatory conditions suitable for treatment with a compound, salt orprodrug of the disclosure may also be categorized based on the one ormore cytokines that are elevated in patients (for example, in a tissueor body fluid (e.g., blood, serum or plasma) of the patient) having theconditions and/or that mediate, in whole or in part, the symptoms of thecondition. In certain embodiments, inflammatory conditions suitable fortreatment are conditions characterized, in whole or in part, by elevatedlevels (e.g., elevated levels in plasma and/or in a tissue in whichsymptoms are present) of one or more of the following cytokines: IL-4,IL-10, and/or IL-12. It should be noted that additional cytokines mayalso be elevated. However, in certain embodiments, the inflammatorycondition is characterized by elevated concentrations, such as elevatedin plasma concentrations, of at least IL-4, IL-10, and/or IL-12.Exemplary conditions that may, in certain embodiments, be characterizedby elevated levels of IL-4, IL-10 and/or IL-12 include, but are notlimited to, rheumatoid arthritis, psoriasis (including plaquepsoriasis), psoriatic arthritis, atherosclerosis, Crohn's disease,irritable bowel syndrome, ulcerative colitis, multiple sclerosis, jointautoimmune inflammation, and immune-mediated inflammatory disorders. Thedisclosure contemplates methods in which a subject in need of treatmentfor any of the foregoing conditions or any condition characterized byelevated levels of IL-4, IL-10, and/or IL-12 may be treated byadministering an effective amount of a compound of the disclosure (e.g.,a compound, salt or prodrug). In certain embodiments, the conditionbeing treated is not Alzheimer's disease and/or the subject in needthereof does not have and/or is not being treated for and/or has notbeen diagnosed with and/or is not suspected of having Alzheimer'sdisease. In certain embodiments, the condition being treated is notParkinson's disease and/or the subject in need thereof is not beingtreated for and/or has not been diagnosed with and/or is not suspectedof having Parkinson's disease. In certain embodiments, the condition ischaracterized by elevated levels of, at least, IL-12, and the disclosureprovides methods for reducing levels of IL-12, such as in the plasma, ofpatients having any of the foregoing conditions or another conditionmediated, in whole or in part, by IL-12 misregulation. Throughout thedisclosure, a reference to an increased (elevated) level orconcentration of one or more cytokines, for example, IL-12, in a subject(for example, in a tissue or body fluid sample of the subject) with aparticular condition, for example, an inflammatory condition, refers toan increased (elevated) level or concentration of the cytokine in asubject with the condition relative to a subject without the condition.

In certain embodiments, a compound, salt, or prodrug of the disclosure(e.g., P₂Y₆ receptor-modulating compounds, salts and/or prodrugs of thedisclosure) is administered to decrease levels of one or more cytokinesin a subject in need thereof (e.g., a subject with an inflammatorycondition). In certain embodiments, levels of cytokine are decreased inthe plasma of the treated subject. Exemplary cytokines that may bedecreased, such as decreased in the plasma of treated subjects, include,but are not limited to, IL-15, IL-1b, IL-2, IL-7, IL-9, IL-10, IL-17,MIG, and MIP1a. Further exemplary cytokines that may be decreased, suchas decreased in the plasma of treated subjects, include, but are notlimited to, IL-3, IL-4, IL-10, IL-12, IFN-r, IL-5, IL-6, IL-13, andMIP1b. In certain embodiments, at least one, at least two, at leastthree, at least four, at least five, at least six, at least seven, atleast eight, at least nine cytokines are decreased following treatment.In certain embodiments, at least IL-4, IL-10, and/or IL-12 are reducedin treated subjects, such as in plasma of treated subjects. In otherwords, in certain embodiments, the disclosure provides a method forreducing the level of one or more of IL-4, IL-10, and/or IL-12 in asubject in need thereof, such as reducing cytokine levels in plasma ofthe subject. In certain embodiments, at least IL-4, IL-10, and IL-12 arereduced in treated subjects, and the disclosure provides a method forreducing levels of IL-4, IL-10, and IL-12 in a subject in need thereof.In certain embodiments, at least IL-12 is reduced in treated subjects.In any of the foregoing, the disclosure contemplates that one or more(e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more than 10) additionalcytokines may also be reduced following treatment. The disclosurecontemplates that, in certain embodiments, administering a compound,salt, or prodrug of the disclosure may result in a statisticallysignificant decrease in levels of a particular cytokine or of one ormore cytokines in plasma in the subject, relative to the levels prior toone or more treatments. However, the disclosure also contemplates thatthe levels of such cytokines or of other cytokines, though reducedfollowing one or more treatments, may be reduced to a lesser degree(e.g., the average level may decrease even if the total change is notstatistically significant). As is common with the administration ofcompounds, the intended affect (e.g., reduction in plasma levels ofcertain cytokines) may require multiple treatments over some period oftime. Thus, the disclosure contemplates that a reduction in cytokinelevels in plasma, or any other affect, may be observable after a singletreatment or after multiple treatments.

Without being bound by theory, the reduction in circulating cytokines inthe plasma may be mediated by actions on macrophages and monocytes,thereby indicating applicability of treatment with a compound, salt, orprodrug of the disclosure to numerous inflammatory conditions. Incertain embodiments, the inflammatory condition is mediated, in whole orin part, by elevated interleukins.

Without being bound by theory, generally suppressing the immune systemmay result in unwanted side effects. Thus, in certain embodiments,administering a compound, salt or prodrug of the disclosure to a patientto treat an inflammatory condition reduces levels of one or morecytokines, but does not generally decrease levels of all cytokines.Thus, in certain embodiments, administering a compound, salt or prodrugof the disclosure does not cause general immunosuppression. For example,in certain embodiments, although the levels of one or more cytokines aredecreased, the levels of one or more of the following are unchanged,substantially unchanged, or even slightly increased followingadministration of a compound, salt or prodrug of the disclosure: M-CSF,GM-CSF, G-CSF, MCP-1, IP-10, MIG, eotaxin, MIP-2, or LIX. In certainembodiments, administering a compound, salt or prodrug of the disclosureto a subject does not result in a statistically significant increase inthe risk of opportunistic infections versus that for subjects having thesame condition but not so treated. In certain embodiments, administeringa compound, salt or prodrug of the disclosure to a subject does notresult in neutropenia.

In certain embodiments, the condition being treated comprises rheumatoidarthritis. In certain embodiments, the patient has elevated levels ofIL-12, such as elevated levels in plasma and/or in synovial tissue.Rheumatoid arthritis is an autoimmune disease and is a chronic, systemicinflammatory disorder. Rheumatoid arthritis primarily affects thejoints, particularly the synovial joints, but it may also affect manyother tissues and organs including the lungs, pericardium, and sclera.The condition can be disabling and painful, and patients whose diseaseis not adequately managed may have significant loss of mobility andsubstantial impairments in daily functioning. Numerous animal models ofrheumatoid arthritis exist and may be used, for example, to optimizetreatment regimens. These models include the collagen-induced arthritismodel, the collagen-antibody-induced arthritis model, thezymosan-induced arthritis model, and the methylated BSA model. Inaddition, genetically manipulated transgenic mouse lines exist andprovide suitable models. For a review of numerous models see Asquith etal., 2009, European Journal of Immunology 39(8): 2040-4.

In certain embodiments, the condition being treated comprises psoriasis,such as plaque psoriasis. In certain embodiments, the condition beingtreated comprises psoriatic arthritis. There are five types ofpsoriasis: plaque, guttate, inverse, pustular, and erythrodermic. Themost common form, plaque psoriasis, is commonly seen as red and whitehues of scaly patches appearing on the epidermis. In certainembodiments, the condition being treated herein is plaque psoriasis.Psoriasis can also cause inflammation of the joints, which is known aspsoriatic arthritis. Approximately 10-30% of patients with psoriasisalso have psoriatic arthritis. In certain embodiments, the disclosureprovides methods for treating psoriatic arthritis. In certainembodiments the patient in need of treatment for psoriasis, such asplaque psoriasis, or for psoriatic arthritis has elevated levels ofIL-12. Animal models of psoriasis are available and may be used, forexample, to optimize treatment regimens. See, for example, Conrad, 2006,Current Rheumatology Report 8(5): 342-347.

In certain embodiments, the condition being treated comprisesatherosclerosis. Atherosclerosis is a condition in which an artery wallthickens as a result of the accumulation of fatty materials such ascholesterol and triglyceride. It affects arterial blood vessels andinvolves a chronic inflammatory response, such as in the walls ofarteries. Animal models are available and may be used, for example, tooptimize treatment regimens. See, for example, Getz, 2012, ArteriosclerThromb Vase Biol. 32(5): 1104-15.

In certain embodiments, the condition being treated is inflammatorybowel disease, such as Crohn's disease or ulcerative colitis. Crohn'sdisease is a type of inflammatory bowel disease that may affect any partof the gastrointestinal tract (e.g., mouth to anus), leading to diverseGI symptoms. Approximately 50% of cases affect both ileum and the largeintestines. The primary symptoms include abdominal pain, diarrhea,vomiting, and/or weight loss. In addition, patients may experiencesymptoms and complications in other tissues and organs, such as anemia,skin rash, arthritis, inflammation of the eye, and fatigue. In somecases, uncontrolled disease may lead to obstruction, fistula, orabscess. Ulcerative colitis affects the colon and is characterized byulcers or open sores. The main symptom of active disease includesconstant diarrhea mixed with blood and/or mucus. The frequency andseverity of the diarrhea varies with the severity of the disease, andthe GI-tract bleeding may lead to anemia. Like with Crohn's disease,non-GI symptoms may also be present. Severe ulcerative colitis can leadto perforation and may be fatal. Numerous animal models to, for example,study inflammatory bowel disease and/or optimize treatment areavailable. See, for example, Mizoguchi, 2012, Prog Mol Biol Transi Sci.105: 263-320.

In certain embodiments, the condition being treated comprises irritablebowel syndrome. Irritable bowel syndrome generally involves asensitization of the nerves responsible for peristalsis. As a result,the muscles controlled by these nerves spasm in response to mildstimuli, such as certain foods or stress. Symptoms include pain,diarrhea, and/or constipation.

In certain embodiments, a compound, salt, and/or prodrug of thedisclosure is administered topically, for example, to decreaseinflammation in an inflammatory skin disorder. In certain embodiments, acompound, salt, and/or prodrug of the disclosure is administeredlocally, for example, injected into the space around an inflamed jointin a subject with rheumatoid arthritis. In certain embodiments, acompound, salt, and prodrug of the disclosure is administeredsystemically, such as orally or intravenously. These are merelyexemplary. The appropriate route of administration may be selected basedon the particular indication being treated and the patient's condition,and numerous exemplary routes of administration are described herein andknown in the art.

The disclosure contemplates methods of treating any one or more of theforegoing diseases or conditions (including categories of diseases orconditions) using a compound, salt or prodrug of the disclosure.

F. Compositions and Modes of Administration

It will be appreciated that compounds and agents, salts and/or prodrugsthereof, used in the compositions and methods of the present disclosurepreferably should readily penetrate the blood-brain barrier whenperipherally administered. Compounds which cannot penetrate theblood-brain barrier, however, can still be effectively administereddirectly into the central nervous system, e.g., by an intraventricularroute.

In some embodiments of this disclosure, the compound, or salt and/orprodrug thereof, of the present disclosure is formulated with apharmaceutically acceptable carrier. In other embodiments, no carrier isused. For example, the compound, or salt and/or prodrug thereof, asdescribed herein can be administered alone or as a component of apharmaceutical formulation (therapeutic composition). The compound, orsalt and/or prodrug thereof, may be formulated for administration in anyconvenient way for use in human medicine.

Pharmaceutically acceptable carriers that may be used in thesecompositions include, but are not limited to, ion exchangers, alumina,aluminum stearate, lecithin, serum proteins, such as human serumalbumin, buffer substances such as phosphates, glycine, sorbic acid,potassium sorbate, partial glyceride mixtures of saturated vegetablefatty acids, water, salts or electrolytes, such as protamine sulfate,disodium hydrogen phosphate, potassium hydrogen phosphate, sodiumchloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulose-based substances, polyethylene glycol, sodiumcarboxymethylcellulose, polyacrylates, waxes,polyethylene-polyoxypropylene-block polymers, polyethylene glycol andwool fat.

In some embodiments, the therapeutic methods of the disclosure includeadministering the composition of a compound or agent, or salt and/orprodrug thereof, topically, systemically, or locally. For example,therapeutic compositions of compounds or agents, salts and/or prodrugsthereof, of the disclosure may be formulated for administration by, forexample, injection (e.g., intravenously, subcutaneously, orintramuscularly), inhalation or insufflation (either through the mouthor the nose) or oral, buccal, sublingual, transdermal, nasal, orparenteral administration. The compositions of compounds or agents,salts and/or prodrugs thereof, described herein may be formulated aspart of an implant or device, or formulated for slow or extendedrelease. When administered parenterally, the therapeutic composition ofcompounds or agents, salts and/or prodrugs thereof, for use in thisdisclosure is preferably in a pyrogen-free, physiologically acceptableform. Techniques and formulations generally may be found in Remington'sPharmaceutical Sciences, Meade Publishing Co., Easton, Pa.

In certain embodiments, pharmaceutical compositions suitable forparenteral administration may comprise the compound, or salt and/orprodrug thereof, of the present disclosure in combination with one ormore pharmaceutically acceptable sterile isotonic aqueous or non-aqueoussolutions, dispersions, suspensions or emulsions, or sterile powderswhich may be reconstituted into sterile injectable solutions ordispersions just prior to use, which may contain antioxidants, buffers,bacteriostats, solutes which render the formulation isotonic with theblood of the intended recipient or suspending or thickening agents.Examples of suitable aqueous and non-aqueous carriers which may beemployed in the pharmaceutical compositions of the disclosure includewater, ethanol, polyols (such as glycerol, propylene glycol,polyethylene glycol, and the like), and suitable mixtures thereof,vegetable oils, such as olive oil, and injectable organic esters, suchas ethyl oleate. Proper fluidity can be maintained, for example, by theuse of coating materials, such as lecithin, by the maintenance of therequired particle size in the case of dispersions, and by the use ofsurfactants.

A composition comprising a compound, or salt and/or prodrug thereof, ofthe present disclosure may also contain adjuvants, such aspreservatives, wetting agents, emulsifying agents and dispersing agents.Prevention of the action of microorganisms may be ensured by theinclusion of various antibacterial and antifungal agents, for example,paraben, chlorobutanol, phenol sorbic acid, and the like. It may also bedesirable to include isotonic agents, such as sugars, sodium chloride,and the like into the compositions. In addition, prolonged absorption ofthe injectable pharmaceutical form may be brought about by the inclusionof agents which delay absorption, such as aluminum monostearate andgelatin.

In certain embodiments of the disclosure, compositions comprising acompound, or salt and/or prodrug thereof, of the present disclosure canbe administered orally, e.g., in the form of capsules, cachets, pills,tablets, lozenges (using a flavored basis, usually sucrose and acacia ortragacanth), powders, granules, or as a solution or a suspension in anaqueous or non-aqueous liquid, or as an oil-in-water or water-in-oilliquid emulsion, or as an elixir or syrup, or as pastilles (using aninert base, such as gelatin and glycerin, or sucrose and acacia) and thelike, each containing a predetermined amount of the compound, or saltand/or prodrug thereof, of the present disclosure as an activeingredient.

In solid dosage forms for oral administration (capsules, tablets, pills,dragees, powders, granules, and the like), one or more compositionscomprising the compound, or salt and/or prodrug thereof, of the presentdisclosure may be mixed with one or more pharmaceutically acceptablecarriers, such as sodium citrate or dicalcium phosphate, and/or any ofthe following: (1) fillers or extenders, such as starches, lactose,sucrose, glucose, mannitol, and/or silicic acid; (2) binders, such as,for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and/or acacia; (3) humectants, such as glycerol;(4) disintegrating agents, such as agar-agar, calcium carbonate, potatoor tapioca starch, alginic acid, certain silicates, and sodiumcarbonate; (5) solution retarding agents, such as paraffin; (6)absorption accelerators, such as quaternary ammonium compounds; (7)wetting agents, such as, for example, cetyl alcohol and glycerolmonostearate; (8) absorbents, such as kaolin and bentonite clay; (9)lubricants, such a talc, calcium stearate, magnesium stearate, solidpolyethylene glycols, sodium lauryl sulfate, and mixtures thereof; and(10) coloring agents. In the case of capsules, tablets and pills, thepharmaceutical compositions may also comprise buffering agents. Solidcompositions of a similar type may also be employed as fillers in softand hard-filled gelatin capsules using such excipients as lactose ormilk sugars, as well as high molecular weight polyethylene glycols andthe like.

Liquid dosage forms for oral administration include pharmaceuticallyacceptable emulsions, microemulsions, solutions, suspensions, syrups,and elixirs. In addition to the compound, or salt and/or prodrugthereof, of the present disclosure, the liquid dosage forms may containinert diluents commonly used in the art, such as water or othersolvents, solubilizing agents and emulsifiers, such as ethyl alcohol(ethanol), isopropyl alcohol, ethyl carbonate, ethyl acetate, benzylalcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, oils(in particular, cottonseed, groundnut, corn, germ, olive, castor, andsesame oils), glycerol, tetrahydrofuryl alcohol, polyethylene glycolsand fatty acid esters of sorbitan, and mixtures thereof. Besides inertdiluents, the oral compositions can also include adjuvants such aswetting agents, emulsifying and suspending agents, sweetening,flavoring, coloring, perfuming, and preservative agents.

Suspensions, in addition to the active compounds, salts and/or prodrugsthereof, may contain suspending agents such as ethoxylated isostearylalcohols, polyoxyethylene sorbitol, and sorbitan esters,microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agarand tragacanth, and mixtures thereof.

A person of ordinary skill in the art, such as a physician, is readilyable to determine the required amount of the compound, or salt and/orprodrug thereof, of the present disclosure to treat the subject usingthe compositions and methods of this disclosure. It is understood thatthe dosage regimen will be determined for an individual, taking intoconsideration, for example, various factors that modify the action of acompound, or salt and/or prodrug thereof, of the present disclosure, theseverity or stage of the disease, route of administration, andcharacteristics unique to the individual, such as age, weight, size, andextent of cognitive impairment.

It is well-known in the art that normalization to body surface area isan appropriate method for extrapolating doses between species. Tocalculate the human equivalent dose (HED) from a dosage used in thetreatment of age-dependent cognitive impairment in rats, the formula HED(mg/kg)=rat dose (mg/kg)×0.16 may be employed (see Estimating the SafeStarting Dose in Clinical Trials for Therapeutics in Adult HealthyVolunteers, December 2002, Center for Biologics Evaluation andResearch). For example, using that formula, a dosage of 10 mg/kg in ratsis equivalent to 1.6 mg/kg in humans. This conversion is based on a moregeneral formula HED=animal dose in mg/kg×(animal weight in kg/humanweight in kg)^(0.33) Similarly, to calculate the HED can be calculatedfrom a dosage used in the treatment in mouse, the formula HED(mg/kg)=mouse dose (mg/kg)×0.08 may be employed (see Estimating the SafeStarting Dose in Clinical Trials for Therapeutics in Adult HealthyVolunteers, December 2002, Center for Biologics Evaluation andResearch).

In certain embodiments of the disclosure, the dose of the compound, orsalt and/or prodrug thereof, or composition of the present disclosure isbetween 0.00001 and 100 mg/kg/day (which, given a typical human subjectof 70 kg, is between 0.0007 and 7000 mg/day). Desired duration ofadministration of the compounds, salts or prodrugs described herein canbe determined by routine experimentation by one skilled in the art. Forexample, the compounds, salts and/or prodrugs of the present disclosuremay be administered for a period of 1-4 weeks, 1-3 months, 3-6 months,6-12 months, 1-2 years, or more, up to the lifetime of the patient. Forexample, daily administration of the compounds over this period iscontemplated.

In addition to compound, or salt and/or prodrug thereof, of the presentdisclosure, the compositions and methods of this disclosure can alsoinclude other therapeutically useful agents. These other therapeuticallyuseful agents may be administered in a single formulation,simultaneously or sequentially with the compound, or salt and/or prodrugthereof, of the present disclosure according to the methods of thedisclosure.

It will be understood by one of ordinary skill in the art that thecompositions and methods described herein may be adapted and modified asis appropriate for the application being addressed and that thecompositions and methods described herein may be employed in othersuitable applications, and that such other additions and modificationswill not depart from the scope hereof. For example, the compounds, saltsand/or prodrugs of the disclosure are also useful as agents foragonizing P₂Y₆ receptor activity, and can be used in vitro or in vivo tostudy normal and abnormal P₂Y₆ receptor function. In certainembodiments, the compounds, salts, and/or prodrugs of the disclosure areused, directly or indirectly, to agonize P₂Y₆ receptor activity, and maybe used in any of the in vitro and/or in vivo methods disclosed herein.In certain embodiments, P₂Y₆ receptor-modulating compounds, salts and/orprodrugs of the disclosure are agonists of the disclosure, and includethe compounds, salts, and/or prodrugs described herein. The disclosurecontemplates that any such compounds, salts, or prodrugs of thedisclosure may be used to treat any of conditions described herein.

This disclosure will be better understood from the Experimental Detailswhich follow. However, one skilled in the art will readily appreciatethat the specific methods and results discussed are merely illustrativeof the disclosure as described more fully in the embodiments whichfollow thereafter.

EXAMPLES Example 1 Preparation of Triethylamine and Sodium Salts ofCompound 6

Scheme 2 below provides a general synthetic route for the preparation ofthe triethylamine (TEA) and sodium salts of compound 6.

Step 1: Synthesis of Compound 47

To a solution of compound 42 (3.0 g, 8.11 mmol) in DMF (90 mL) was addedY01 (3.0 g, 16.22 mmol) and K₂CO₃ (4.47 g, 16.22 mmol), the resultingmixture was stirred at 70° C. for 1 h. After cooling down, the mixturewas diluted with 250 mL water, extracted with ethyl acetate (EA) (250mL×3), the organic layer was dried over anhydrous Na₂SO₄, concentratedto give a crude product. The crude product was purified on column(eluted with PE/EA=3:1) to give 3.61 g 47 as a colorless oil, yield:94%. ¹H NMR (300 MHz, CDCl₃) δ 7.36 (d, J=8.1 Hz, 1H), 7.32-7.27 (m,4H), 7.25-7.18 (m, 1H), 5.98 (d, J=4.0 Hz, 1H), 5.81 (d, J=8.1 Hz, 1H),5.34 (d, J=2.4 Hz, 2H), 4.35 (s, 3H), 4.13 (m, 2H), 3.01-2.84 (m, 2H),2.14 (dd, J=12.1, 4.2 Hz, 9H), 1.26 (t, J=7.1 Hz, 1H).

Step 2: Synthesis of Compound 48

3.61 g 47 was dissolved in 150 mL 5N NH₃/methanol then stirred at roomtemperature for 12 hrs. After the reaction was finished, methanol wasremoved under vacuum to give the crude product. The crude product wasrecrystallized from EA to give 1.94 g 48 as a white solid, yield: 73%.¹H NMR (300 MHz, DMSO) δ 7.95 (d, J=8.1 Hz, 1H), 7.37-7.11 (m, 5H), 5.77(m, 2H), 5.42 (d, J=5.4 Hz, 1H), 5.12 (m, 1H), 4.06-3.88 (m, 4H), 3.84(m, 1H), 3.64 (m, 1H), 3.53 (m, 1H), 2.80 (t, J=9.0 Hz, 2H).

Step 3: Synthesis of the Triethylamine (TEA) Salt of Compound 6

To a solution of compound 48 (500 mg, 1.44 mmol) in 7.2 mL trimethylphosphate was added proton sponge (460 mg, 2.15 mmol) under nitrogenatmosphere followed by POCl₃ (290 mg, 1.87 mmol) at 0° C. After 1 h ofstirring at 0-4° C., tri-n-butylamine (192 mg, 1.04 mmol) was added tothe solution followed by 7.2 mL of 0.5M tri-n-butylammonium phosphatesolution in dimethylformamide (DMF). After 5 min the mixture was pouredinto a cold 0.5M aqueous TEAB solution (45 mL, pH 7.5) and stirred at 0°C. for 10 min. The solution was allowed to warm to room temperature uponstirring and then left standing for 1 h. The mixture was extracted withtert-butyl methyl ether (50 mL×3), the aqueous solution was evaporatedand lyophilized to yield white solid. The white solid was purified onprep-HPLC to give 82.8 mg compound 6 TEA salt, yield: 7.1%. ¹H NMR (300MHz, D₂O) δ 7.82 (d, J=8.1 Hz, 1H), 7.23-7.08 (m, 5H), 5.83 (d, J=8.1Hz, 1H), 5.73 (d, J=4.0 Hz, 1H), 4.23-3.93 (m, 7H), 3.12-2.94 (m, 16H),2.78 (t, J=7.0 Hz, 2H), 1.14 (t, J=7.3 Hz, 24H).

Step 4: Synthesis of the Sodium Salt of Compound 6

82.8 mg compound 6 TEA salt was changed to sodium salt by ion exchangeresin to give Compound 6 sodium salt, 58.9 mg, yield: 100%. ¹H NMR (300MHz, D₂O) δ 7.84 (d, J=8.1 Hz, 1H), 7.20 (m, 5H), 5.87 (d, J=8.1 Hz,1H), 5.76 (d, J=4.3 Hz, 1H), 4.24-4.02 (m, 7H), 2.86 (t, J=7.1 Hz, 2H).³¹P NMR (162 MHz, D₂O) δ −9.68 (d, J=20.7 Hz, 1P), −11.00 (d, J=20.9 Hz,1P).

Example 2 Preparation of Triethylamine and Sodium Salts of Compound 3

Scheme 3 below provides a general synthetic route for the preparation ofthe triethylamine (TEA) and sodium salts of compound 3.

Step 1: Synthesis of Compound 49

Compound 49 was prepared from compound 42 according to the sameprocedure as described in step 1 of Example 1. 2.98 g compound 49 wasobtained from 3.0 g compound 42, yield: 79.7%. ¹H NMR (300 MHz, CDCl₃) δ8.47 (d, J=4.7 Hz, 1H), 7.58 (m, 1H), 7.43 (d, J=8.2 Hz, 1H), 7.19-7.07(m, 2H), 6.01 (d, J=4.8 Hz, 1H), 5.85 (d, J=8.2 Hz, 1H), 5.36-5.26 (m,2H), 5.20 (s, 2H), 4.31 (s, 3H), 2.05 (t, J=10.5 Hz, 9H).

Step 2: Synthesis of Compound 50

Compound 50 was prepared from compound 49 according to the sameprocedure as described in step 2 of Example 1. 1.79 g compound 50 wasobtained from 2.98 g compound 49, yield: 82.7%. ¹H NMR (300 MHz, DMSO) δ8.42 (d, J=3.5 Hz, 1H), 8.03 (d, J=8.1 Hz, 1H), 7.76-7.67 (m, 1H),7.26-7.18 (m, 2H), 5.81 (dd, J=14.9, 6.5 Hz, 2H), 5.44 (d, J=5.7 Hz,1H), 5.23-5.01 (m, 4H), 4.03 (m, 1H), 3.96 (m, 1H), 3.84 (m, 1H),3.70-3.59 (m, 1H), 3.53 (m, 1H).

Step 3: Synthesis of the TEA Salt of Compound 3

The TEA salt of compound 3 was prepared from compound 50 according tothe same procedure as described in step 3 of Example 1. 8.6 mg compound3 TEA salt was obtained from 100 mg compound 50, yield: 4%. ¹H NMR (300MHz, D₂O) δ 8.38-8.26 (m, 1H), 7.96 (d, J=8.2 Hz, 1H), 7.74 (m, 1H),7.34-7.19 (m, 2H), 5.94 (m, 2H), 5.13 (d, J=2.8 Hz, 2H), 4.32-4.27 (m,2H), 4.21-4.11 (m, 3H), 3.08 (q, J=7.3 Hz, 13H), 1.16 (t, J=7.3 Hz,23H).

Step 4: Synthesis of the Sodium Salt of Compound 3

The sodium salt of compound 3 was prepared from the TEA salt of compound3 according to the same procedure as described in step 4 of Example 1.24.9 mg compound 3 sodium salt was obtained from 31 mg compound 3 TEAsalt, yield: 99%. ¹H NMR (300 MHz, D₂O) δ 8.31 (d, J=4.4 Hz, 1H), 7.98(d, J=8.1 Hz, 1H), 7.73 (t, J=7.8 Hz, 1H), 7.25 (d, J=7.7 Hz, 2H), 6.01(d, J=8.1 Hz, 1H), 5.86 (d, J=3.8 Hz, 1H), 5.12 (s, 2H), 4.28 (m, 5H).³¹P NMR (162 MHz, D₂O) δ −6.73 (d, J=21.9 Hz), −10.54 (d, J=21.9 Hz).

Example 3 Preparation of Triethylamine and Sodium Salts of Compound 4

Scheme 4 below provides a general synthetic route for the preparation ofthe triethylamine (TEA) and sodium salts of compound 4.

Step 1: Synthesis of Compound 51

To a solution of compound 42 (1.061 g, 1.87 mmol), Y03 (930 mg, 5.73mmol) and PPh₃ (1.501 g, 5.73 mmol) in 25 mL THF was added dropwise asolution of DIAD (1.159 g, 5.73 mmol) in 5 mL THF over 30 min, theresulting mixture was stirred at 50° C. for 3 h. After the reaction wasfinished, THF was removed to give the crude product. The crude productwas purified on column (eluted with EA) to give 1.37 g compound 51 as anoil, yield: 88.8%.

Step 2: Synthesis of Compound 52

Compound 52 was prepared from compound 51 according to the sameprocedure as described in step 2 of Example 1. 0.8 g compound 52 wasobtained from 1.37 g compound 51, yield: 77.4%. ¹H NMR (300 MHz, DMSO) δ7.99 (d, J=8.1 Hz, 1H), 7.73 (d, J=8.2 Hz, 1H), 7.55 (d, J=8.5 Hz, 1H),7.36 (t, J=7.7 Hz, 1H), 7.09 (t, J=7.5 Hz, 1H), 5.87-5.76 (m, 2H), 5.38(d, J=5.7 Hz, 1H), 5.30 (d, J=4.0 Hz, 2H), 5.12-5.06 (m, 1H), 4.01 (t,J=5.2 Hz, 1H), 3.94 (s, 4H), 3.84 (d, J=3.6 Hz, 1H), 3.68-3.46 (m, 2H).

Step 3: Synthesis of the TEA Salt of Compound 4

The TEA salt of compound 4 was prepared from compound 52 according tothe same procedure as described in step 3 of Example 1. 8.1 mg compound4 TEA salt was obtained from 100 mg compound 52, yield: 4%. ¹H NMR (300MHz, D₂O) δ 7.91 (d, J=8.1 Hz, 1H), 7.68 (d, J=8.2 Hz, 1H), 7.43-7.34(m, 2H), 7.11 (m, 1H), 5.98 (d, J=8.1 Hz, 1H), 5.88 (d, J=4.2 Hz, 1H),5.32 (d, J=1.9 Hz, 2H), 4.26 (m, 2H), 4.15 (m, 3H), 3.86 (s, 3H), 3.07(q, J=7.3 Hz, 12H), 1.23-1.09 (t, J=7.3 Hz, 20H).

Step 4: Synthesis of the Sodium Salt of Compound 4

The sodium salt of compound 4 was prepared from the TEA salt of compound4 according to the same procedure as described in step 4 of Example 1.64.3 mg compound 4 sodium salt was obtained from 80 mg compound 4 TEAsalt, yield: 98%. ¹H NMR (300 MHz, D₂O) δ 7.74 (d, J=8.1 Hz, 1H), 7.32(d, J=8.0 Hz, 1H), 6.96 (m, 1H), 6.79 (m, 2H), 5.84 (d, J=8.1 Hz, 1H),5.73 (d, J=4.1 Hz, 1H), 4.92 (s, 2H), 4.29-4.06 (m, 5H), 3.55 (s, 3H).³¹P NMR (162 MHz, D₂O) δ −9.88 (d, J=19.7 Hz, 1P), −10.82 (d, J=19.7 Hz,1P).

Example 4 Preparation of Triethylamine and Sodium Salts of Compound 1

Scheme 5 below provides a general synthetic route for the preparation ofthe triethylamine (TEA) and sodium salts of compound 1.

Step 1: Synthesis of Compound 53

Compound 53 was prepared from compound 42 according to the sameprocedure as described in step 1 of Example 1. A crude product ofcompound 53 was obtained from 1.14 g compound 42. The crude product wasused in the next step directly without further purification.

Step 2: Synthesis of Compound 54

Compound 54 was prepared from compound 53 according to the sameprocedure as described in step 2 of Example 1. 700 mg compound 54 wasobtained from the 1.14 g compound 53, yield: 59.2%. ¹H NMR (300 MHz,DMSO) δ 7.99 (d, J=9.0 Hz, 1H), 7.46-7.52 (m, 5H), 5.72-5.82 (m, 2H),5.07-5.10 (m, 1H), 4.45-4.55 (m, 2H), 3.92-4.00 (m, 2H), 3.86 (s, 1H),3.54-3.64 (m, 2H), 3.30-3.32 (m, 1H).

Step 3: Synthesis of the TEA Salt of Compound 1

The TEA salt of compound 1 was prepared from compound 54 according tothe same procedure as described in step 3 of Example 1. 8.6 mg compound1 TEA salt was obtained from 100 mg compound 54, yield: 5%. ¹H NMR (300MHz, D₂O) δ 7.80 (d, J=8.2 Hz, 1H), 7.41 (m, 5H), 5.85 (d, J=8.2 Hz,1H), 5.72 (d, J=4.4 Hz, 1H), 4.49 (m, 2H), 4.12 (m, 6H), 3.07 (q, J=7.3Hz, 4H), 1.16 (t, J=7.3 Hz, 6H).

Step 4: Synthesis of the Sodium Salt of Compound 1

The sodium salt of compound 1 was prepared from the TEA salt of compound1 according to the same procedure as described in step 4 of Example 1.28.3 mg compound 1 sodium salt was obtained from 30 mg compound 1 TEAsalt, yield: 100%. ¹H NMR (300 MHz, D₂O) δ 7.88 (d, J=8.2 Hz, 1H),7.50-7.38 (m, 5H), 5.89 (d, J=8.2 Hz, 1H), 5.73 (d, J=4.1 Hz, 1H), 4.55(m, 2H), 4.31-4.04 (m, 5H). ³¹P NMR (162 MHz, D₂O) δ −8.13 (d, J=21.6Hz, 1P), −10.86 (d, J=21.7 Hz, 1P).

Example 5 Preparation of Triethylamine and Sodium Salts of Compound 5

Scheme 5 below provides a general synthetic route for the preparation ofthe triethylamine (TEA) and sodium salts of compound 5.

Step 1: Synthesis of Compound 55

Compound 55 was prepared from compound 42 according to the sameprocedure as described in step 1 of Example 1. 4.2 g compound 55 wasobtained from 3.0 g compound 42, yield: 100%. ¹H NMR (300 MHz, CDCl₃) δ7.79 (d, J=8.0 Hz, 1H), 7.53 (dd, J=3.7, 1.6 Hz, 2H), 7.45 (d, J=8.2 Hz,1H), 7.30 (m, 1H), 6.04 (d, J=4.7 Hz, 1H), 5.89 (d, J=8.2 Hz, 1H), 5.50(d, J=1.7 Hz, 2H), 5.33 (m, 2H), 4.34 (d, J=4.3 Hz, 3H), 2.10 (d, J=6.6Hz, 6H), 2.04 (s, 3H).

Step 2: Synthesis of Compound 56

Compound 56 was prepared from compound 55 according to the sameprocedure as described in step 2 of Example 1. 2.36 g compound 56 wasobtained from 4.2 g compound 55, yield: 75.6%. ¹H NMR (300 MHz, DMSO) δ8.06 (d, J=8.2 Hz, 2H), 7.86 (d, J=8.0 Hz, 2H), 7.76-7.61 (m, 4H), 7.39(t, J=7.4 Hz, 2H), 5.89 (d, J=7.9 Hz, 2H), 5.80 (m, 2H), 5.38-5.42 (m,3H), 5.16 (m, 1H), 3.85-4.04 (m, 2H), 3.50-3.66 (m, 2H).

Step 3: Synthesis of the TEA Salt of Compound 5

The TEA salt of compound 5 was prepared from compound 56 according tothe same procedure as described in step 3 of Example 1. 26.3 mg compound5 TEA salt was obtained from 300 mg compound 56, yield: 5%. ¹H NMR (300MHz, D₂O) δ 7.80 (d, J=8.2 Hz, 1H), 7.51 (d, J=7.9 Hz, 1H), 7.42-7.35(m, 1H), 7.31 (m, 1H), 7.12 (t, J=7.3 Hz, 1H), 5.90 (d, J=8.2 Hz, 1H),5.80 (d, J=4.0 Hz, 1H), 5.22 (s, 2H), 4.27-4.00 (m, 6H), 2.98 (q, J=7.3Hz, 7H), 1.07 (t, J=7.3 Hz, 10H).

Step 4: Synthesis of the Sodium Salt of Compound 5

The sodium salt of compound 5 was prepared from the TEA salt of compound5 according to the same procedure as described in step 4 of Example 1.51.5 mg compound 5 sodium salt was obtained from 55 mg compound 5 TEAsalt, yield: 99%. ¹H NMR (300 MHz, D₂O) δ 7.98 (d, J=8.2 Hz, 1H), 7.75(d, J=8.0 Hz, 1H), 7.63-7.54 (m, 2H), 7.35 (m, 1H), 6.03 (d, J=8.2 Hz,1H), 5.89 (d, J=4.2 Hz, 1H), 5.45 (s, 2H), 4.31 (m, 2H), 4.15 (m, 3H).³¹P NMR (162 MHz, D₂O) δ −7.95 (d, J=21.2 Hz, 1P), −10.80 (d, J=21.5 Hz,1P).

The sodium salts of compounds 44-49 were prepared according to similarsynthetic procedures as those used for preparing compound 5 (see Scheme5 above). The characterization of these sodium salts are summarized inTable 1 below.

TABLE 1 Characterization of compounds 44-49: Compound Characterization

44 White solid, yield: 3% ¹H NMR (400 MHz, D2O): δ 7.92 (1H, d, J = 8Hz), 7.51-7.52 (1H, m), 7.21-7.25 (1H, m), 7.01-7.06 (1H, m), 5.98 (1H,d, J = 8.4 Hz), 5.88 (1H, d, J = 4 Hz), 5.38 (2H, s), 4.25-4.24 (2H, m),4.16-4.11 (3H, m). ³¹P NMR (400 MHz, D2O): δ −10.78 (1P, d, J = 15.4Hz), −11.36 (1P, d, J = 15.5 Hz).

45 White solid, yield: 3% ¹H NMR (400 MHz, D2O): δ 8.01 (1H, d, J = 8Hz), 7.58-7.56 (1H, m), 7.40-7.31 (2H, m), 6.04 (1H, d, J = 8.4 Hz),5.90 (1H, s), 5.48 (1H, s), 4.37-4.30 (2H, m), 4.18-4.17 (3H, m). ³¹PNMR (400 MHz, D2O): δ −6.87 (1P, d, J = 16.1 Hz), −10.91 (1P, d, J =16.7 Hz).

46 White solid yield: 4.6% ¹H NMR (400 MHz, D2O): δ 8.02 (1H, d, J = 8Hz), 7.48 (1H, d, J = 7.2 Hz), 7.38 (1H, d, J = 8.4 Hz), 7.14 (1H, d, J= 7.2 Hz), 6.05 (1H, d, J = 8.0 Hz), 5.90 (1H, s), 5.60 (1H, s),4.34-4.31 (2H, m), 4.22-4.20 (3H, m). ³¹P NMR (400 MHz, D2O): δ −5.79(1P, d, J = 14.2 Hz), −10.01 (1P, d, J = 13.7 Hz).

47 White solid, yield: 5.3% ¹H NMR (400 MHz, D2O): δ 7.98 (1H, d, J = 8Hz), 7.44 (1H, s), 7.39 (1H, s), 6.01 (1H, d, J = 8.0 Hz), 5.86 (1H, d,J = 4.0 Hz), 5.37 (2H, s), 4.35-4.33 (1H, m), 4.28-4.26 (1H, m),4.16-4.15 (3H, m). ³¹P NMR (400 MHz, D2O): δ −6.57 (1P, d, J = 16.7 Hz),−10.87 (1P, d, J = 16.7 Hz).

48 White solid, yield: 5.3% ¹H NMR (400 MHz, D2O): δ 7.96 (1H, d, J = 8Hz), 7.57 (1H, d, J = 8 Hz), 7.35 (1H, s), 7.16 (1H, d, J = 8 Hz), 6.01(1H, d, J = 8.0 Hz), 5.89 (1H, d, J = 4.0 Hz), 5.40 (2H, s), 4.30-4.26(2H, m), 4.18-4.11 (3H, m), 2.40 (3H, s). ³¹P NMR (400 MHz, D2O): δ−10.35 (1P, d, J = 15.3 Hz), −11.32 (1P, d, J = 15.4 Hz).

49 White solid, yield: 3% ¹H NMR (400 MHz, D2O): δ 7.97 (1H, d, J = 8Hz), 7.51 (1H, d, J = 8 Hz), 7.35 (1H, d, J = 8 Hz), 7.21 (1H, d, J = 8Hz), 6.03 (1H, d, J = 8.0 Hz), 5.91 (1H, d, J = 4.0 Hz), 5.41 (2H, s),4.30-4.28 (2H, m), 4.21-4.12 (3H, m), 2.40 (3H, s). ³¹P NMR (400 MHz,D2O): δ −10.73 (1P, d, J = 15.3 Hz), −11.33 (1P, d, J = 15.1 Hz).

Example 6 Materials and Methods for In Vitro and In Vivo Studies

Activation of P₂Y₆ Receptor

Synthetic ligands were tested for activation of P₂Y₆ receptor bymeasuring receptor induced Ca²⁺ changes with the fluorescent Ca²⁺indicator fluo-4. 1321N1 human astrocytoma cell lines either expressingP₂Y₂, P₂Y₄ or P₂Y₆ receptors were plated into 24-well plates. Two daysafter plating, fluorometric measurements were made and responses ofcells to a serial dilution of ligands were determined. P₂Y₆receptor-mediated Ca²⁺ fluorescent change was determined by normalizedaccumulation of fluorescent change of 3 timepoints after ligandadministration subtracted by value from ACSF control. Changes influorescent intensity were plotted corresponding to ligand concentrationin GraphPad. Dose-response curve and EC₅₀ for each ligand was estimatedusing nonlinear curve fit and Sigmoidal dose-response analysis. Thesodium salt of compound 5 exhibited an EC₅₀ of 12 nM. The sodium salt ofcompound 5 was demonstrated to selectively activate P₂Y₆ receptors bycomparing its Ca²⁺ mobilizing effects in three 1321N1 human astrocytomacell lines expressing P₂Y₂, P₂Y₄ or P₂Y₆ receptors. The sodium salt ofcompound 5 was only effective at elevating Ca²⁺ levels when applied tocells expressing P₂Y₆ receptors and not effective in P₂Y₂, or P₂Y₄receptor expressing cells. The ability of the sodium salt of compound 5to elevate Ca²⁺ signals in P₂Y₆ expressing cells was attenuated byaddition of the P₂Y₆ receptor antagonist MRS2578.

PSAPP Mice

Heterozygous mutant (K670N/M671L) APP (50% C57B6, 50% SJL) transgenicmice were crossed with heterozygous mutant (A246E) PS-1 (50% C57B6, 50%SJL) transgenic mice to generate heterozygous PSAPP transgenic mice(also referred to as PS-1/APP or PSAPP+/+ mice), which refers to animalsheterozygous for the PS-1 A246E transgene and the APP K670N/M671Ltransgene. Non-transgenic control animals were littermates (alsoreferred to as PSAPP_−/− mice) generated in the breeding for PSAPPtransgenic animals. Mouse genotype was determined by Polymerase ChainReaction (PCR). Both male and female mice of 6-7 months old were usedfor the experiments below. All animal experiments were performed inaccordance with the Tufts Animal Care and Use Committee and withnational regulations and policies.

Two-Photon In Vivo Imaging Study

In this study, PSAPP mice were anesthetized using isoflurane and athin-skull preparation was used to minimize the surface damage. Amyloidplaques were visualized with methoxyX04 labeling and blood plasma waslabeled with Rhodamine dextran to facilitate re-localization of the sameimaging area. Stack images were obtained using a two-photon system(Prairie Technologies) with excitation at 850 nm. The emission wasdetected by external photomultiplier tubes (525/70; DLCP 575; 607/45nm).

Stereotaxic Injection

Animals were anesthetized and immobilized in a stereotaxic frame. Foreach injection, 1 μl of 10 mM UDP or other suitable compounds inartificial cerebrospinal fluid (ACSF) as the vehicle were injectedintraventricularly using the following coordinates: AP 0.2 mm, ML 1 mm,and DV 2.2 mm.

Histology and Immunohistochemistry

Mice were perfused transcardially with 4% paraformaldehyde and 40 mCoronal sections were collected. Sections were sequentially incubated in0.3% H₂O₂ for 10 minutes, blocking solution for 2 hrs, blocking solutioncontaining the primary antibody (rabbit anti-beta1-42; rabbitanti-beta1-40, from Chemicon International and rat anti-CD45) for 48hours at 4° C., and blocking solution containing biotinylated antibodyor fluorescently-labeled antibody for 2 hours at room temperature.Sections were visualized in a bright field microscope or a confocalmicroscope, and the optical density was obtained using MetaMorphsoftware.

Fear Conditioning Test

On day one, animals were trained in a fear conditioning apparatus for atotal of 7 minutes with a two-pairing paradigm of cue and mild footshock (a 30-s acoustic-conditioned stimulus, 80 dB; a 2-s shockstimulus, 0.5 mA). To evaluate contextual fear learning, the animalswere returned to the training context 24 hours post-training, andfreezing behavior was scored for 5 minutes. Freezing behavior wasmonitored by MotorMonitor (Hamilton Kinder) and scored every 5 seconds.

Electrophysiology and Long-Term Potentiation (LTP) Recording

Hippocampal slices (350 μm thick) were prepared from 6-month-old PSAPPmice. Baseline responses were obtained every 10 seconds and Input-output(I/O) curves, paired-pulse modification and LTP were successivelymeasured. The stimulation intensity was set to a level that gives avalue of 30% of the maximum obtained. LTP were induced by high frequencystimulation (HFS, 100 pulses at 100 Hz, four times) or by theta-burststimulation (TBS, 10 bursts at 5 Hz, repeated 10 times in 15 sintervals).

Example 7 Dose-Dependent Activation of P₂Y₆ Receptor

Synthetic ligands were tested for activation of P₂Y₆ receptor bymeasuring receptor induced Ca²⁺ changes with the fluorescent Ca²⁺indicator fluo-4, and results are shown in FIG. 10(A)-(K). 1321N1 humanastrocytoma cell lines either expressing P₂Y₂, P₂Y₄ or P₂Y₆ receptorswere plated into 24-well plates. Two days after plating, fluorometricmeasurements were made and responses of cells to a serial dilution ofligands were determined. P₂Y₆ receptor-mediated Ca²⁺ fluorescent changewas determined by normalized accumulation of fluorescent change of 3timepoints after ligand administration subtracted by value from ACSFcontrol. Changes in fluorescent intensity were plotted corresponding toligand concentration in GraphPad. Dose-response curve and EC₅₀ for eachligand was estimated using nonlinear curve fit and Sigmoidaldose-response analysis. The sodium salt of compound 5 exhibited an EC₅₀of 12 nM. The sodium salt of compound 5 was demonstrated to selectivelyactivate P₂Y₆ receptors by comparing its Ca²⁺ mobilizing effects inthree 1321N1 human astrocytoma cell lines expressing P₂Y₂, P₂Y₄ or P₂Y₆receptors. The sodium salt of compound 5 was only effective at elevatingCa²⁺ levels when applied to cells expressing P₂Y₆ receptors and noteffective in P₂Y₂, or P₂Y₄ receptor expressing cells. The ability of thesodium salt of compound 5 to elevate Ca²⁺ signals in P₂Y₆ receptorexpressing cells was attenuated by addition of the P₂Y₆ receptorantagonist MRS2578. These experiments demonstrated that compound 5 is aP₂Y₆ receptor agonist.

Example 8 Acute UDP Administration Reduced Plaque Burden in PSAPP Mice

To evaluate the effect of UDP on plaque burden, two-photon microscopywas used to assess the amyloid plaques in the barrel cortex in livingPSAPP mice. Amyloid plaques were stained by systemically administeredmethoxy-X04. One day prior to imaging, PSAPP mice were injected withmethoxyX04 to label the amyloid plaques. On the imaging day, tofacilitate the re-location of the same imaging area, blood plasma waslabeled with Rhodamine dextran. Images were obtained from the samestart- and end-point to ensure the same image volume.

The results were shown in a maximum intensity projection of afluorescent stack containing 45 planes. Representative images ofmethoxyX04 labeled amyloid plaques and angiopathy on days 1 are shown inFIG. 1(A)-(C). Immediately after imaging, animals were injected withACSF or UDP intracerebroventricularly (i.c.v.) and allowed to recover.On day 4, animals were subjected to a second period of imaging of thesame regions studied on day 1 and the results are shown in FIG.1(D)-(F). The similar pattern of angiopathy (shown by open arrows)indicated the same imaging area.

Overall, decreased plaque occupied-area was observed on day 4 followingadministration of UDP. In the images with higher magnification (FIGS.1(C) and (F)), the same dense core plaques (as shown by arrows) could beidentified based on its morphology and location relative to the bloodvessel. It was observed that the dense core plaques had more intensemethoxyX04 labeling, but with decreased plaque size (as shown byarrows), when compared to the size of the same plaques on day 1. Thissuggested that acute UDP treatment reduced plaques size in live animals.This effect was further evaluated by quantifying the number of plaques,plaque load, and size of cross-section of individual plaques. See FIG.2(A)-(E). Quantitative analysis showed that acute UDP treatment led to a12.6% reduction in the number of plaques (P<0.01) and a 17.2% reductionin plaque load (P<0.01) in barrel cortex as assessed by two-photonmicroscopy. Individual identified plaques that were detected on thesecond imaging session showed an 18.2% reduction (P<0.01) incross-sectional area following UDP treatment.

After repeated imaging, brains were fixed and subjected to postmortemimmunohistochemistry with amyloid beta specific antibodies β1-40 andβ1-42 to evaluate the plaque load (area occupied by immunostaining ofplaque) in cortex and hippocampus. See FIG. 3(A)-(D). UDP treatmentresulted in a 60% (p<0.05) and 62% (p<0.01) decrease in plaque load inthe cortex and hippocampus, respectively, as assessed by staining withthe β1-40 antibody. Quantification of staining with β1-42 antibodyshowed a 48% (P<0.01) and 47% (P<0.05) decrease in plaque load in thecortex and hippocampus, respectively. See FIG. 4(A)-(F). Both in vivoimaging and post hoc staining showed decrease in plaque burden in brainsof PSAPP mice, consistent with reduced plaque load in the tested animalsfollowing acute administration of UDP (e.g., a P₂Y₆ receptor agonist).

Example 9 Activation of P₂Y₆ Receptors Reduced Plaque Burden in PSAPPMice

3-phenacyl-UDP (also referred to as PSB0474) is a potent and selectiveP₂Y₆ receptor agonist (EC50=70 nM, >500-fold selective). In this study,P₂Y₆ receptor was activated in vivo using 3-phenacyl-UDP (PSB0474). Theeffect of this activation may have on plaque burden was also evaluated.

PSB0474 was systemically administered to PSAPP mice via intraperitonealinjection for 2, 4 and 6 consecutive days. In one group, prior toevaluation and following to administration for 6 consecutive days,treatment was suspended for two weeks (6+2 weeks group). Brains werethen fixed and plaque load was evaluated by immunostaining with theamyloid beta specific antibodies: β1-40 and β1-42. Representative imagesof plaque load in cortex and hippocampus from animals that receivedinjections of PSB0474 according to the foregoing injection schedules areshown in FIG. 5(A)-(D). Quantitative data showed that administration ofPSB0474 for 4 and 6 consecutive days significantly decreasedimmunoreactivity of β1-40 in both cortex and hippocampus (FIGS. 6(A) and6(B)). Whereas, when administration of PSB0474 was stopped for 2 weeksfollowing six consecutive days of treatment (denoted as the 6+2 weeksgroup), β1-40 staining rebounded; although to a level lower thanobserved in mice treated with saline as a vehicle control. FIGS. 6A and6B depict the reduction in plaque load (%) the cortex and hippocampus,respectively, in PSAPP mice after treatment with 3-phenacyl-UDP for 2,4, or 6 consecutive days, as assayed by staining with the β1-40antibody. FIGS. 6C-6F depict data obtained following administration ofdifferent dosages of PSB0474. It is important to note that a 1000×increase in dose of PSB0474 did not cause detrimental effects to theanimal, suggesting that there is a wide therapeutic window for P2Y₆receptor agonists. However, with the higher dose of 1 mg/kg we didobserve smaller effects on the efficacy endpoint presumably because theenhanced receptor occupancy led to some desensitization/internalizationof the P2Y₆ receptor. This result indicates that activation of P₂Y₆receptor significantly attenuated plaque load in both the cortex andhippocampus in PSAPP mice.

Example 10 Acute UDP Administration Improved Cognitive Function andHippocampal LTP in PSAPP Mice

Amyloid beta peptide has been reported to be toxic to synaptictransmission, and accumulation of amyloid protein is associated withcognitive impairment both in animal models of AD and in AD patients.Additionally, accumulation of amyloid protein is observed in otherconditions associated with cognitive impairment, such as in DownSyndrome. Therefore, we further investigated in PSAPP mice whether theobserved reduction in plaque burden would also lead to reversal incognitive and memory deficits typically observed in AD patients, such asimpaired cognition, impaired memory, and deficits in long-termpotentiation (LTP).

In this study, the fear conditioning associative learning paradigm wasused as a rapid cognition assay for PSAPP mice. This study allowed us toprobe cognitive function with a single training day followed in 24 hoursby tests for contextual and cued fear learning. Contextual fear learningis dependent upon a brain area that has been implicated as a locus forcognitive decline in AD: the hippocampus. Two pairings of CS-US for fearconditioning were followed 24 hours later by testing for contextual andcued fear learning. Previous studies have reported that PSAPP animalsappear to have a selective hippocampus-dependent impairment inassociative learning following two pairings of conditioned stimuli forfear conditioning.

In this study, it was found that PSAPP mice treated with ACSF showed lowfreezing behavior during 5 minute-testing time (FIG. 7(A)), which issimilar to the level reported in previous study (Dineley, et al. 2002).After UDP treatment, PSAPP mice exhibited increased freezing behaviorduring the first 4 minutes but not during the last minute. Analysis oftotal freezing percentage (FIGS. 7(B) and 7(C)) showed that PSAPP micetreated with acute UDP exhibited significantly higher freezing behavior(49%±5%) compared to an animal treated with ACSF (18%±3%). This datasuggested that acute UDP treatment rescued the deficit in contextualfear learning in PSAPP mice.

In the fear conditioning test mice exhibit a freezing behavior if theyhave a memory of the application of the aversive shock that wasdelivered 24 hours earlier. When placed in the appropriate environmentthe mice “freeze” and do not explore their environment as theyanticipate the delivery of an additional shock. Thus the greater percenttime that they exhibit freezing indicates a greater memory of theirprevious experience and thus improved memory. This represents a decreasein the cognitive impairment observed in the untreated mice.

Accumulated evidence has shown that amyloid peptides naturally secretedor isolated from Alzheimer's brains impair synaptic plasticity,especially hippocampal long-term potentiation (Walsh et al., 2002).Therefore, we further performed LTP recordings in PASPP mice andinvestigated whether P₂Y₆ receptor-mediated plaque clearance affectssynaptic plasticity. In this study, LTP was successfully induced in CA1area of the hippocampus in aged PSAPP mice with high-frequencystimulation (HFS, 100 pulses at 100 Hz, four times in 20 s intervals).First, it was observed that LTP at the schaffer collateral synapsewithin the CA1 region was depressed in PSAPP mice, as compared withlittermates (FIG. 8(A)). This result confirmed previous reports aboutsynaptic toxicity of Abeta. Acute UDP treatment reversed this LTPdeficit in PSAPP mice, and the LTP significantly increased compared withmice injected with ACSF (FIG. 8(B)). Analysis of the last 15 minpotentiation showed a significant increase in field excitatorypostsynaptic potential (fEPSP) in PSAPP mice treated with UDP, which iscomparable to the level in PSAPP littermates (FIG. 8(C)). These datasupports the conclusion that activation of P₂Y₆ receptor rescues the LTPdeficiency in PSAPP mice, which is consistent with improvement incognition mediated by P₂Y₆ receptor.

Example 11 Activation of P₂Y₆ Receptor with Chronic Injection of PSB0474Improved Cognitive Function of PSAPP Mice

Similar to acute UDP treatment, chronic injection of the P₂Y₆ receptoragonist 3-phenacyl-UDP (PSB0474) increased total freezing percentage incontext test in PSAPP mice (FIG. 9(A)-(C)). In this study, PSB0474 wasadministered at two different doses, both of which showed beneficialeffect in improving cognitive function in the PSAPP mice.

Example 12 Activation of P₂Y₆ Receptor with Compound 5 ImprovedCognitive Function of PSAPP Mice and Reduced Plaque Burden in PSAPP Mice

In this study, compound 5 was injected intraperitoneally into 6 to7-month-old PSAPP and WT mice daily at two different doses, i.e., 1μg/kg or 1 mg/kg of compound 5 (in 1% DMSO/PBS) for 7 consecutive days.Consistent with the results observed following acute UDP or PSB0474treatment, treatment with compound 5 increased total freezing percentagein the context test in PSAPP mice (see FIG. 11). FIG. 11 shows freezingbehavior (freezing %) of PASPP mice in fear conditioning studies aftertreatment with vehicle control or compound 5. FIG. 11 depicts theresults of experiments using the contextual fear conditioning test withPSAPP mice treated with vehicle control (black bar at center of graph).These mice showed significantly decreased freezing percentage comparedto the age-matched wildtype animals (white bar); indicative of thememory deficits and cognitive impairment in PSAPP mice. Administrationof compound 5 prior to testing significantly improved the freezingbehavior (hatched bar at right of graph) compared to the controltreatment. In fact, this behavior which is indicative of cognitivefunction and memory was restored to a level equivalent to that observedin wildtype animals. This result is consistent with the conclusion thatcompound 5 improved cognitive function (decreased cognitive deficits) inthese mice, such as by improving memory and/or learning.

Treatment with compound 5 was also found to reduce the plaque burden incortex and hippocampus of PSAPP mice (FIG. 12 (A)-(C)). FIG. 12 showsplaque load in the cortex (Cx) and hippocampus (Hp) of the PSAPP miceafter treatment with compound 5 or vehicle control, as assayed using theamyloid beta specific antibody β1-42. FIG. 12A depicts the substantialdecrease in Aβ plaque load (%) in the cortex following treatment withcompound 5, in comparison to the vehicle control. FIG. 12 B depicts thesubstantial decrease in Aβ plaque load (%) in the hippocampus followingtreatment with compound 5, in comparison to the vehicle control. FIG.12C shows postmortem immunohistochemistry analysis of the plaque load incortex and hippocampus of PSAPP mice after treatment with compound 5 orvehicle control. Amyloid beta specific antibody β1-42 was used in theanalysis.

To generate these graphs showing plaque load, mice were euthanized,brain sections cut and antibodies directed against Aβ 42 were used todisclose Aβ plaques. Images were acquired digitally and an algorithm wasapplied to threshold the image so that plaques were isolated from thebackground. The algorithm then calculated the percent area of the fieldof view occupied by the plaques.

In addition to rodent models, such as described above, compounds, saltsand prodrugs of the present disclosure may be tested in canine modelsfor human neurodegenerative diseases, such as dogs with caninecounterpart of Alzheimer's disease. For example, an aged beagle model isavailable from InterVivo (see, the website on the world wide webintervivo.com/aged-dog/ad). Other models have been reported in theliterature, such as by Insua et al., Neurobiol Aging, 2010, 31(4):625-635 (epub 2008 Jun. 24, doi: 10.1016/j.neurobiolaging.2008.05.014).

Further, ADME (Absorption, Distribution, Metabolism and Excretion) andToxicity (ADMET) Studies for safety, tolerability, and pharmacokinetic(PK) profiles of the compounds, salts and prodrugs of the presentdisclosure are conducted in rodents and a second species (such as dogs).

Example 13 Administration of Compound 5 Decreased Levels of CirculatingCytokines in the Plasma of PSAPP Mice

Inflammatory cytokines were assessed in mouse plasma of both wild typeand PS1/APP mice (Alzheimer's mouse model) and the impact ofintraperitoneal delivery of compound 5 on circulating cytokines wasassessed. Seven daily intraperitoneal injections of 1 μg/kg of compound5 were delivered to mice. 24 hours following the final injection, plasmawas collected. Wildtype, age matched littermates and PSAPP mice (>6months of age) were treated either with vehicle (phosphate bufferedsaline) or vehicle containing compound. Compared to wildtype mice, PSAPPmice exhibited greater levels of several cytokines (where cytokinelevels were measured in pg/ml. In particular IL-9, IL-15 and MIG wereelevated compared to WT vehicle controls. Treatment with compoundreduced the levels of several cytokines in PSAPP mice including Il-1β,IL-2, IL-7, IL-9, IL-10, IL-15, MIG and MIP1α. Additionally, treatmentreduced the levels of certain cytokines in wildtype animals (e.g. IL-2and IL-10) supporting the conclusion that agonizing P₂Y₆ receptoractivity, directly or indirectly, affects inflammatory cytokines moregenerally (e.g., not specifically in Alzheimers models). See FIG. 13.

Example 14 Pre-Symptomatic Administration to PSAPP Mice Reduced Amyloid3 Accumulation and Reduced Impairment

In this study, treatment of PSAPP mice commenced when the mice werepre-symptomatic. Specifically, treatment was initiated when the micewere approximately 3 months old. PSAPP mice were treated for 100 dayswith daily, intraperitoneal injections of 10 μg/kg of the nucleoside ofcompound 5 or with vehicle. We discovered that the nucleoside ofcompound 5 has activity similar to that of compound 5 in terms ofmodulating P₂Y₆ receptor activity. Without being bound by theory, whenthe nucleoside of compound 5 is administered, it may be phosphorylatedto produce compound 5 (e.g., converted to compound 5), which is capableof agonizing P₂Y₆ receptor activity. Accordingly, data obtained withthis particular nucleoside is reflective of administration of compound5.

Following treatment, mice were assessed in a fear conditioning task formemory formation. Subsequently, plaque burden in the mice was alsoevaluated. The data provided in Examples 14 and 15 is for 19 vehicletreated mice and 22 compound treated mice. The data provided for thevehicle-treated group is the average across those mice, and error barsdepict the standard error (SEM). Similarly, the data provided for thecompound-treated group is the average across those mice, and the errorbars depict the SEM.

Treatment with the nucleoside of compound 5 prevented impairment ofcontextual fear memory. In other words, treatment decreased loss ofmemory that otherwise develops and is observed in PSAPP mice. Memory isassessed by the percent time that mice “freeze” 24 hours after a fearinducing electric shock. The greater the freezing the greater the memoryof the prior shock. As depicted in FIG. 14, the mice treated with thenucleoside of compound 5 show a statistically significant increase inthis freezing time, as compared to vehicle treated mice.

In addition, mice treated with the nucleoside of compound 5 had reducedplaque burden. This reflects a reduction in amyloid 3 accumulation inthe compound-treated mice versus the vehicle-treated mice. See FIG. 15.

Example 15 Decreased Levels of Cytokines in the Plasma of PSAPP Mice

As part of the study described in Example 14, the levels of numerouscytokines in plasma of mice treated with vehicle or the nucleoside ofcompound 5 were also evaluated. As described in Example 14, treatmentwas initiated when the mice were approximately 3 months old. PSAPP micewere treated for 100 days with daily injections of 10 μg/kg of thenucleoside of compound 5 or vehicle. Following treatment and the fearconditioning task experiment, plasma was taken for multiplex cytokineanalysis of circulating cytokine levels in vehicle-treated versuscompound-treated PSAPP mice. Cytokine levels are assayed using amulti-plex system where beads are labelled with capture antibodyspecific for each analyte tested. Each bead set is coupled to a specificcapture antibody and is distinguishable from beads coupled to adifferent capture antibody. Thus, the levels of each analyte can beevaluated and distinguished. These results are summarized in FIGS.16-19, and levels of each analyte are shown in pg/ml.

Briefly, following treatment for 100 days with the nucleoside ofcompound 5, which maybe converted to compound 5 in vivo, a statisticallysignificant reduction, in plasma concentrations of IL-4, IL-10, andIL-12 (also referred to as IL-12(p70)) was observed, in comparison tovehicle control treated mice. See FIG. 16. For IL-12, the reductionobserved represents an actual reduction in the functional IL-12,heterodimeric cytokine, and not just a reduction in the p40 subunitcommon to multiple cytokines. Specifically, the data examining the p40subunit alone (depicted as IL-12(p40); using a capture antibody thatmeasures the p40 subunit) does not reflect a change following treatmentwith the compound while the IL-12(p70) data shows a statisticallysignificant reduction following treatment with the compound (see FIG.16). Regardless of the mechanism of action by which IL-12 is reduced,these results indicate that it is not merely via a mechanism generic toall cytokines that share the p40 subunit. Throughout the application, werefer to a reduction in IL-12 cytokine levels interchangeably byreference to either “IL-12” or “IL-12(p70)”.

In addition, the average plasma levels of numerous other cytokines, suchas IFN-r, IL-1β, IL-2, IL-3, IL-5, IL-6, IL-7, IL-9, IL-13, IL-17, LIF,MIP-1α, and MIP-1β, were also reduced. However, administration of thecompound did not result in overall immunosuppression, as the levels ofseveral cytokines were not changed in treated mice. For example, no orsubstantially no change in the levels of M-CSF, MIP-2, Eotaxin, GM-CSF,G-CSF, LIX, MCP-1, IL-1α and IP-10 was observed.

What is claimed is:
 1. A method for treating an inflammatory ocularcondition in a subject in need thereof, comprising administering to thesubject a therapeutically effective amount of a compound of formula I:

or a salt thereof, wherein: A is a 3- to 10-membered aromatic ornon-aromatic ring having up to 5 heteroatoms independently selected fromN, O, S, SO, or SO₂, wherein the aromatic or non-aromatic ring isindependently and optionally substituted with one or more R⁷; X isindependently selected from —O—, —S—, —N(R⁵)— and a (C1-C3)-aliphaticgroup independently and optionally substituted with one or more R⁴; Y isa bond or a (C1-C5)-aliphatic group independently and optionallysubstituted with one or more R⁴; Z and W are each independently selectedfrom ═O, ═S, ═N(R⁵), and ═NOR⁵; R¹ is selected from: —H, halogen, —OR⁵,—CN, —CF₃, —OCF₃ and a (C1-C6)-aliphatic group optionally substitutedwith one or more R⁷; R² and R³ are each independently selected from—OR⁵, —SR⁵, —NR⁵R⁶, —OC(O)R⁵, —OC(O)NR⁵R⁶, and —OC(O)OR⁵; eachoccurrence of R⁴ is independently selected from: halogen, —OR⁵, —NO₂,—CN, —CF₃, —OCF₃, —R⁵, 1,2-methylenedioxy, 1,2-ethylenedioxy, —N(R⁵)₂,—SR⁵, —SOR⁵, —SO₂R⁵, —SO₂N(R⁵)₂, —SO₃R⁵, —C(O)R⁵, —C(O)C(O)R⁵,—C(O)CH₂C(O)R⁵, —C(S)R⁵, —C(S)OR⁵, —C(O)OR⁵, —C(O)C(O)OR⁵,—C(O)C(O)N(R⁵)₂, —OC(O)R⁵, —C(O)N(R⁵)₂, —OC(O)N(R⁵)₂, —C(S)N(R⁵)₂,—(CH₂)₀₋₂NHC(O)R⁵, —N(R⁵)N(R⁵)COR⁵, —N(R⁵)N(R⁵)C(O)OR⁵,—N(R⁵)N(R⁵)CON(R⁵)₂, —N(R⁵)SO₂R⁵, —N(R⁵)SO₂N(R⁵)₂, —N(R⁵)C(O)OR⁵,—N(R⁵)C(O)R⁵, —N(R⁵)C(S)R⁵, —N(R⁵)C(O)N(R⁵)₂, —N(R⁵)C(S)N(R⁵)₂,—N(COR⁵)COR⁵, —N(OR⁵)R⁵, —C(═NH)N(R⁵)₂, —C(O)N(OR⁵)R⁵, —C(═NOR⁵)R⁵,—OP(O)(OR⁵)₂, —P(O)(R⁵)₂, —P(O)(OR⁵)₂, or —P(O)(H)(OR⁵); each occurrenceof R⁵ is independently selected from: H—, (C1-C12)-aliphatic-,(C3-C10)-cycloalkyl- or -cycloalkenyl-, [(C3-C10)-cycloalkyl or-cycloalkenyl]-(C1-C12)-aliphatic-, (C6-C10)-aryl-,(C6-C10)-aryl-(C1-C12)aliphatic-, (C3-C10)-heterocyclyl-,(C6-C10)-heterocyclyl-(C1-C12)aliphatic-, (C5-C10)-heteroaryl-, and(C5-C10)-heteroaryl-(C1-C12)-aliphatic-; wherein two R⁵ groups bound tothe same atom optionally form a 3- to 10-membered aromatic ornon-aromatic ring having up to 3 heteroatoms independently selected fromN, O, S, SO, or SO₂, wherein said ring is optionally fused to a(C6-C10)aryl, (C5-C10)heteroaryl, (C3-C10)cycloalkyl, or a(C3-C10)heterocyclyl; and wherein each R⁵ group is independently andoptionally substituted with one or more R⁷; R⁶ is selected from: —R⁵,—C(O)R⁵, —C(O)OR⁵, —C(O)N(R⁵)₂ and —S(O)₂R⁵; each occurrence of R⁷ isindependently selected from: halogen, —OR⁸, —NO₂, —CN, —CF₃, —OCF₃, —R⁸,oxo, thioxo, 1,2-methylenedioxy, 1,2-ethylenedioxy, —N(R⁸)₂, —SR⁸,—SOR⁸, —SO₂R⁸, —SO₂N(R⁸)₂, —SO₃R⁸, —C(O)R⁸, —C(O)C(O)R⁸, —C(O)CH₂C(O)R⁸,—C(S)R⁸, —C(S)OR⁸, —C(O)OR⁸, —C(O)C(O)OR⁸, —C(O)C(O)N(R⁸)₂, —OC(O)R⁸,—C(O)N(R⁸)₂, —OC(O)N(R⁸)₂, —C(S)N(R⁸)₂, —(CH₂)₀₋₂NHC(O)R⁸,—N(R⁸)N(R⁸)COR⁸, —N(R⁸)N(R⁸)C(O)OR⁸, —N(R⁸)N(R⁸)CON(R⁸)₂, —N(R⁸)SO₂R⁸,—N(R⁸)SO₂N(R⁸)₂, —N(R⁸)C(O)OR⁸, —N(R⁸)C(O)R⁸, —N(R⁸)C(S)R⁸,—N(R⁸)C(O)N(R⁸)₂, —N(R⁸)C(S)N(R⁸)₂, —N(COR⁸)COR⁸, —N(OR⁸)R⁸,—C(═NH)N(R⁸)₂, —C(O)N(OR⁸)R⁸, —C(═NOR⁸)R⁸, —OP(O)(OR⁸)₂, —P(O)(R⁸)₂,—P(O)(OR⁸)₂, or —P(O)(H)(OR⁸); and each occurrence of R⁸ isindependently selected from: H— and (C1-C6)-aliphatic.
 2. The method ofclaim 1, wherein the inflammatory ocular condition is selected from thegroup consisting of uveitis, conjunctivitis, scleritis, andkeratoconjunctivitis sicca.
 3. The method of claim 2, wherein thecompound is

or a pharmaceutically acceptable salt thereof.
 4. The method of claim 1,wherein the compound is

or a pharmaceutically acceptable salt thereof.